feat(files): store files on the host when a channel has no file domain

Chat stays usable when the file service is off or down. Files up to 256 MB are hosted like chat; downloads try the host first and fall back to file-service tickets.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com> [CI]

.woodpecker/dev-image-api.yml

@@ -0,0 +1,51 @@
+# 主后端(含内嵌前端)的开发镜像:提交信息带 [CI],并且这次推送改到了主后端用到的代码时才构建。
+# 推送 webdrop-api:dev(开发机器的 podman auto-update 跟踪它)和 webdrop-api:dev-<提交>
+when:
+  - event: push
+    branch: [master, main]
+    evaluate: 'CI_COMMIT_MESSAGE contains "[CI]"'
+    path:
+      include:
+        - 'web/**'
+        - 'packages/core/**'
+        - 'server/Containerfile'
+        - 'server/Directory.Build.props'
+        - 'server/src/WebDrop.Api/**'
+        - 'server/src/WebDrop.Core/**'
+        - 'server/src/WebDrop.Storage/**'
+        - 'server/src/WebDrop.Frontend/**'
+        - 'server/src/WebDrop.FileProtocol/**'
+        - 'server/src/WebDrop.Sync/**'
+        - 'scripts/ci-publish-image.sh'
+        - '.woodpecker/dev-image-api.yml'
+  - event: manual
+
+labels:
+  ci: domain-linux-native
+  platform: linux/amd64
+
+clone:
+  - name: git
+    image: woodpeckerci/plugin-git:2.9.3
+    settings:
+      remote:
+        from_secret: gitea_clone_webdrop
+      lfs: false
+
+depends_on:
+  - ci
+  - web-build
+
+concurrency: 1
+
+steps:
+  publish-dev-image:
+    image: bash
+    environment:
+      ZOT_USERNAME: justme
+      ZOT_SECRET:
+        from_secret: zot_secret
+      ZOT_REGISTRY: registry.oeo.one
+    commands:
+      - sha="${CI_COMMIT_SHA:0:7}"
+      - bash scripts/ci-publish-image.sh webdrop-api server/Containerfile "dev-$sha" dev

.woodpecker/dev-image-files.yml

@@ -0,0 +1,46 @@
+# 文件服务(fileAPI)的开发镜像:提交信息带 [CI],并且这次推送改到了文件服务用到的代码时才构建。
+# 推送 webdrop-files:dev(放文件的机器上的 podman auto-update 跟踪它)和 webdrop-files:dev-<提交>
+when:
+  - event: push
+    branch: [master, main]
+    evaluate: 'CI_COMMIT_MESSAGE contains "[CI]"'
+    path:
+      include:
+        - 'server/Containerfile.files'
+        - 'server/Directory.Build.props'
+        - 'server/src/WebDrop.FileApi/**'
+        - 'server/src/WebDrop.FileProtocol/**'
+        - 'server/src/WebDrop.Sync/**'
+        - 'scripts/ci-publish-image.sh'
+        - '.woodpecker/dev-image-files.yml'
+  - event: manual
+
+labels:
+  ci: domain-linux-native
+  platform: linux/amd64
+
+clone:
+  - name: git
+    image: woodpeckerci/plugin-git:2.9.3
+    settings:
+      remote:
+        from_secret: gitea_clone_webdrop
+      lfs: false
+
+# 文件服务不带前端,不用等前端构建
+depends_on:
+  - ci
+
+concurrency: 1
+
+steps:
+  publish-dev-image:
+    image: bash
+    environment:
+      ZOT_USERNAME: justme
+      ZOT_SECRET:
+        from_secret: zot_secret
+      ZOT_REGISTRY: registry.oeo.one
+    commands:
+      - sha="${CI_COMMIT_SHA:0:7}"
+      - bash scripts/ci-publish-image.sh webdrop-files server/Containerfile.files "dev-$sha" dev

.woodpecker/dev-image.yml

@@ -1,51 +0,0 @@
-when:
-  - event: push
-    branch: master
-    evaluate: 'CI_COMMIT_MESSAGE contains "[CI]"'
-  - event: push
-    branch: main
-    evaluate: 'CI_COMMIT_MESSAGE contains "[CI]"'
-
-labels:
-  ci: domain-linux-native
-  platform: linux/amd64
-
-clone:
-  - name: git
-    image: woodpeckerci/plugin-git:2.9.3
-    settings:
-      remote:
-        from_secret: gitea_clone_webdrop
-      lfs: false
-
-depends_on:
-  - ci
-  - web-build
-
-concurrency: 1
-
-steps:
-  publish-dev-image:
-    image: bash
-    environment:
-      ZOT_USERNAME: justme
-      ZOT_SECRET:
-        from_secret: zot_secret
-      ZOT_REGISTRY: registry.oeo.one
-    commands:
-      - set -euo pipefail
-      - ': "${WOODPECKER_BACKEND_LOCAL_TEMP_DIR:=$HOME/woodpecker/work}"'
-      - buildah_store="$(dirname "$WOODPECKER_BACKEND_LOCAL_TEMP_DIR")/buildah-cache/webdrop"
-      - mkdir -p "$buildah_store/storage" "$buildah_store/run"
-      - 'buildah() { command buildah --root "$buildah_store/storage" --runroot "$buildah_store/run" "$@"; }'
-      - printf '%s' "$ZOT_SECRET" | buildah login --tls-verify=true --username "$ZOT_USERNAME" --password-stdin "$ZOT_REGISTRY"
-      - trap 'buildah logout "$ZOT_REGISTRY" >/dev/null 2>&1 || true' EXIT
-      - sha="${CI_COMMIT_SHA:0:7}"
-      - build_tag="dev-$sha"
-      - image="$ZOT_REGISTRY/justme/webdrop-api:dev-$sha"
-      - dev_image="$ZOT_REGISTRY/justme/webdrop-api:dev"
-      - build_time="$(date -u +%Y-%m-%dT%H:%M:%SZ)"
-      - buildah bud --layers --network host --format oci --platform linux/amd64 --build-arg "WEBDROP_FRONTEND_COMMIT=$CI_COMMIT_SHA" --build-arg "WEBDROP_FRONTEND_TAG=$build_tag" --build-arg "WEBDROP_BACKEND_COMMIT=$CI_COMMIT_SHA" --build-arg "WEBDROP_BACKEND_TAG=$build_tag" --build-arg "WEBDROP_BUILD_TIME=$build_time" --tag "$image" --file server/Containerfile .
-      - buildah tag "$image" "$dev_image"
-      - buildah push "$image" "docker://$image"
-      - buildah push "$dev_image" "docker://$dev_image"

.woodpecker/release.yml

@@ -1,3 +1,6 @@
+# 发布:打 vMAJOR.MINOR.PATCH tag(或手动运行并传 RELEASE_TAG)。
+# 一个 tag 同时发布两个镜像:webdrop-api:<tag> / :latest 和 webdrop-files:<tag> / :latest。
+# 两边共用票据格式和文件协议,版本号一致最不容易配错;各机器只会拉自己用的那个镜像。
 when:
   - event: tag
     ref: refs/tags/v*
@@ -37,29 +40,26 @@ steps:
       - NUGET_PACKAGES="$HOME/.cache/woodpecker/webdrop/nuget" dotnet restore server/WebDrop.slnx
       - NUGET_PACKAGES="$HOME/.cache/woodpecker/webdrop/nuget" dotnet test server/WebDrop.slnx --configuration Release --verbosity minimal --no-restore
 
-  publish-backend:
+  publish-api:
     image: bash
+    depends_on: [release-checks]
     environment:
       ZOT_USERNAME: justme
       ZOT_SECRET:
         from_secret: zot_secret
       ZOT_REGISTRY: registry.oeo.one
     commands:
-      - set -euo pipefail
       - release_tag="${CI_COMMIT_TAG:-${RELEASE_TAG:-}}"
-      - test -n "$release_tag"
-      - ': "${WOODPECKER_BACKEND_LOCAL_TEMP_DIR:=$HOME/woodpecker/work}"'
-      - buildah_store="$(dirname "$WOODPECKER_BACKEND_LOCAL_TEMP_DIR")/buildah-cache/webdrop"
-      - mkdir -p "$buildah_store/storage" "$buildah_store/run"
-      - 'buildah() { command buildah --root "$buildah_store/storage" --runroot "$buildah_store/run" "$@"; }'
-      - printf '%s' "$ZOT_SECRET" | buildah login --tls-verify=true --username "$ZOT_USERNAME" --password-stdin "$ZOT_REGISTRY"
-      - trap 'buildah logout "$ZOT_REGISTRY" >/dev/null 2>&1 || true' EXIT
-      - image="$ZOT_REGISTRY/justme/webdrop-api:$release_tag"
-      - latest_image="$ZOT_REGISTRY/justme/webdrop-api:latest"
-      - build_commit="$(git rev-parse HEAD)"
-      - build_time="$(date -u +%Y-%m-%dT%H:%M:%SZ)"
-      - buildah bud --layers --network host --format oci --platform linux/amd64 --build-arg "WEBDROP_FRONTEND_COMMIT=$build_commit" --build-arg "WEBDROP_FRONTEND_TAG=$release_tag" --build-arg "WEBDROP_BACKEND_COMMIT=$build_commit" --build-arg "WEBDROP_BACKEND_TAG=$release_tag" --build-arg "WEBDROP_BUILD_TIME=$build_time" --tag "$image" --file server/Containerfile .
-      - buildah tag "$image" "$latest_image"
-      - buildah push "$image" "docker://$image"
-      - buildah push "$latest_image" "docker://$latest_image"
+      - bash scripts/ci-publish-image.sh webdrop-api server/Containerfile "$release_tag" latest
 
+  publish-files:
+    image: bash
+    depends_on: [release-checks]
+    environment:
+      ZOT_USERNAME: justme
+      ZOT_SECRET:
+        from_secret: zot_secret
+      ZOT_REGISTRY: registry.oeo.one
+    commands:
+      - release_tag="${CI_COMMIT_TAG:-${RELEASE_TAG:-}}"
+      - bash scripts/ci-publish-image.sh webdrop-files server/Containerfile.files "$release_tag" latest

README.md

@@ -19,6 +19,7 @@
 | 文档 | 内容 |
 |---|---|
 | [docs/threat-model.md](docs/threat-model.md) | 信任边界、攻击者模型、每种模式的保证、元数据泄露、不做的事 |
+| [docs/e2ee-boundary-comparison.md](docs/e2ee-boundary-comparison.md) | 当前信任边界、签名授权/事件的目标设计与分阶段路线 |
 | [docs/protocol.md](docs/protocol.md) | 密钥派生、令牌、帧格式、加密和 padding、校验算法、保留策略(协议权威文档) |
 | [docs/api.md](docs/api.md) | HTTP / WebSocket / SSE 接口、鉴权头、错误码 |
 | [docs/architecture.md](docs/architecture.md) | 组件、技术栈、NativeAOT 约束、存储模型、部署、阶段划分 |
@@ -32,9 +33,9 @@
 
 ## 核心概念
 
-- **频道**:唯一的顶层概念,一条只追加的帧流,有自己的 id、密钥、设置和席位。
+- **频道**:唯一的顶层概念,一条只追加的帧流,有自己的 id、密钥、设置和账号成员人数上限。
 - **条目**:频道里的一项内容(文本、JSON、文件),由若干帧组成,可复制、下载、删除。
-- **终端**:加入频道的设备或会话,占一个席位(默认 2 个)。
+- **成员**:频道里的人是用户(账号);设备只是账号的属性,同一账号的多设备只算一人,请求凭账号会话鉴权。频道强制登录,没有未登录访客(便捷分享不受影响)。
 - **所有者 / 成员**:所有者持有管理密钥,成员通过频道链接加入。
 - **模式**:`enc`(默认,浏览器端 AES-256-GCM)和 `raw`(负载原样,服务器可见,用于公开或用户自行加密的内容)。
 

contracts/api-contract.json

@@ -1,3 +1,3 @@
 {
-  "version": "2.1.0"
+  "version": "8.2.0"
 }

deploy/webdrop-dev.container

@@ -10,6 +10,7 @@ PublishPort=127.0.0.1:5001:5000
 Environment=ASPNETCORE_URLS=http://+:5000
 Environment=WebDrop__DataDir=/data
 Environment=DOTNET_EnableDiagnostics=0
+EnvironmentFile=-%h/podman/webdrop-dev/webdrop.env
 Volume=%h/podman/webdrop-dev/data:/data:Z,U
 ReadOnly=true
 ReadOnlyTmpfs=false

deploy/webdrop-files-dev.container

@@ -0,0 +1,29 @@
+[Unit]
+Description=WebDrop file service (fileAPI) development environment from registry
+Wants=network-online.target
+After=network-online.target
+
+[Container]
+ContainerName=webdrop-files-dev
+Image=registry.oeo.one/justme/webdrop-files:dev
+Pull=missing
+AutoUpdate=registry
+PublishPort=127.0.0.1:5101:5100
+Environment=ASPNETCORE_URLS=http://+:5100
+Environment=FileApi__DataDir=/data
+Environment=DOTNET_EnableDiagnostics=0
+EnvironmentFile=%h/podman/webdrop-files-dev/webdrop-files.env
+Volume=%h/podman/webdrop-files-dev/data:/data:Z,U
+ReadOnly=true
+ReadOnlyTmpfs=false
+Tmpfs=/tmp:rw,noexec,nosuid,size=16m
+DropCapability=ALL
+NoNewPrivileges=true
+
+[Service]
+Restart=always
+TimeoutStartSec=120
+TimeoutStopSec=60
+
+[Install]
+WantedBy=default.target

deploy/webdrop-files.container

@@ -0,0 +1,31 @@
+[Unit]
+Description=WebDrop file service (fileAPI)
+Wants=network-online.target
+After=network-online.target
+
+[Container]
+ContainerName=webdrop-files
+# 正式环境:跟踪打 v* tag 发布的 latest。放文件的机器(例如家里的 NAS)只拉这个镜像,不需要主后端的
+Image=registry.oeo.one/justme/webdrop-files:latest
+Pull=missing
+AutoUpdate=registry
+PublishPort=127.0.0.1:5100:5100
+Environment=ASPNETCORE_URLS=http://+:5100
+Environment=FileApi__DataDir=/data
+Environment=DOTNET_EnableDiagnostics=0
+# 和主后端共用的密钥、允许的页面来源、备份设置等,不进仓库。例子见 webdrop-files.env.example
+EnvironmentFile=%h/podman/webdrop-files/webdrop-files.env
+Volume=%h/podman/webdrop-files/data:/data:Z,U
+ReadOnly=true
+ReadOnlyTmpfs=false
+Tmpfs=/tmp:rw,noexec,nosuid,size=16m
+DropCapability=ALL
+NoNewPrivileges=true
+
+[Service]
+Restart=always
+TimeoutStartSec=120
+TimeoutStopSec=60
+
+[Install]
+WantedBy=default.target

deploy/webdrop-files.env.example

@@ -0,0 +1,18 @@
+# 文件服务(家里的 NAS)的机器配置:复制到 ~/podman/webdrop-files/webdrop-files.env 并按实际情况修改。不要提交真实值
+# 和主后端共用的密钥,至少 32 个字符。两边必须一致
+FileApi__Secret=
+# 页面所在的源:浏览器直接把文件传到这里,必须列出,否则浏览器会拦下跨域请求
+FileApi__CorsOrigins__0=https://app.example.com
+# 创建频道时可选的文件空间档位(字节)和默认值;不配用内置的 1/5/10/50/100 GiB,默认 10 GiB
+# FileApi__QuotaChoices__0=1073741824
+# FileApi__QuotaChoices__1=10737418240
+# FileApi__DefaultQuota=10737418240
+# 文件服务最多存多少字节,0 为不限
+# FileApi__MaxStoreBytes=0
+# 每天把新增的文件备份到 S3 协议的存储
+# FileApi__Backup__Enabled=true
+# FileApi__Backup__Time=04:30
+# FileApi__Backup__S3__Endpoint=https://s3.example.com
+# FileApi__Backup__S3__Bucket=webdrop
+# FileApi__Backup__S3__AccessKey=
+# FileApi__Backup__S3__SecretKey=

deploy/webdrop.container

@@ -1,15 +1,21 @@
 [Unit]
 Description=WebDrop API with embedded frontend
+Wants=network-online.target
+After=network-online.target
 
 [Container]
 ContainerName=webdrop
-Image=localhost/webdrop:local
-Pull=never
+# 正式环境:跟踪打 v* tag 发布的 latest。podman-auto-update.timer 每隔几分钟检查 registry,有新镜像就拉取并重启这个单元
+Image=registry.oeo.one/justme/webdrop-api:latest
+Pull=missing
+AutoUpdate=registry
 PublishPort=127.0.0.1:5000:5000
 Environment=ASPNETCORE_URLS=http://+:5000
 Environment=WebDrop__DataDir=/data
 Environment=DOTNET_EnableDiagnostics=0
-Volume=/home/justme/podman/webdrop/data:/data:Z,U
+# 机器上的配置(文件服务的地址和共用密钥等),不进仓库。例子见 webdrop.env.example
+EnvironmentFile=-%h/podman/webdrop/webdrop.env
+Volume=%h/podman/webdrop/data:/data:Z,U
 ReadOnly=true
 ReadOnlyTmpfs=false
 Tmpfs=/tmp:rw,noexec,nosuid,size=16m

deploy/webdrop.env.example

@@ -0,0 +1,7 @@
+# 主后端(VPS)的机器配置:复制到 ~/podman/webdrop/webdrop.env 并按实际情况修改。不要提交真实值
+# 打开文件服务:文件内容不放主后端,由 fileAPI 保存;主后端只签发访问票据
+WebDrop__Files__Enabled=true
+# 浏览器访问文件服务的地址(必须 https,和文件服务机器上配的对外地址一致)
+WebDrop__Files__PublicUrl=https://files.example.com
+# 和文件服务共用的密钥,至少 32 个字符:openssl rand -base64 48。两边必须一致
+WebDrop__Files__Secret=

docs/account-channel-architecture.md

@@ -4,36 +4,44 @@
 
 ## 领域边界
 
-Account 使用不可修改的 username 作为当前版本稳定身份，displayName/avatar 为可修改的个人资料。AccountSettings 与资料在加密保险库中同步。AccountDevice 是账号下的一个浏览器安装身份，具有独立登录 session、名称与撤销状态；每个频道的设备 S 继续独立生成。ChannelMember 绑定账号与频道角色，不绑定某一次登录或某个设备。
+### 已确认的下一版规则
 
-Channel 是成员权限和内容加密的共同边界。Thread 属于 Channel，Folder 属于 Thread，文件与消息必须属于 Thread。Thread 不再创建第二套成员、密钥或网络连接；当前频道成员可读取该频道所有 thread。创建频道时自动建立“常规”thread，用户可继续创建其他 thread，分别上传文件或发消息。
+注册设置初始密码。密码和绑定的 Passkey 是账号认证/解锁入口，不要求旧设备批准新设备；Passkey 的 WebAuthn 验证由 .NET 10 官方组件完成。支持 PRF 时浏览器封装保险库解密凭据；PRF 输出不传给服务器。不支持 PRF 的 Passkey 可登录，资源解密仍需密码。绑定需重新验证密码，撤销后该凭据不能再创建会话。
+
+Member 加入空间后自动获得默认频道的聊天读取/发言和文件读取/上传权，只能修改自己的内容，不能管理频道或邀请成员。其他频道单独授权；历史聊天和文件由 Owner 分别决定是否向新成员开放。历史选择在接受邀请时生效：关闭时分别轮换该数据域 epoch，仅给新成员当前 epoch；已获授权的成员保留历史访问。之后修改开关只影响后续邀请，不撤回已交付密钥。
+
+Account 使用不可修改的 username 作为稳定身份，displayName/avatar 由后端个人资料接口管理。AccountDevice 是账号下的浏览器身份，具有独立登录 session、名称与撤销状态；每个空间的设备 S 独立生成。空间成员绑定账号与角色，不绑定某次登录或设备。
+
+空间是成员管理与同步的边界，不是内容密钥边界。频道属于空间，分组归属空间，文件夹属于频道，资源归属由后端校验和保存。新空间与初始“常规”频道在同一事务中创建。每频道独立维护 chat 与 files 两个数据域及 epoch；分组仅组织频道，不创建密钥域。
 
 ## 模块互通
 
-账号模块提供当前身份、个人资料、设备会话与解锁后的账号密钥。频道模块负责创建/邀请/接受/打开频道、thread 和文件目录。加密模块不读取 UI 或数据库，只提供账号密钥封装、频道凭据封装和帧加解密。Worker 是三者的编排入口，组件经 store/action 调用它。
+账号模块提供当前身份、个人资料、设备会话与解锁后的账号密钥。空间模块负责创建空间、初始频道、成员邀请与加入；频道模块负责频道、分组、文件夹和频道内的聊天/文件访问。权限、历史范围、epoch 和授权收件人由后端计算、持久化和校验。浏览器只根据服务端返回的授权计划生成密钥并进行封装；它不能选择或扩大授权集合。加密模块不读取 UI 或数据库，只提供账号密钥封装、随机对象密钥封装和帧加解密。Worker 是 API 与密码学之间的编排层，不是业务规则来源。
 
 账号登录授权访问服务端；频道内容密钥授权解密内容。这两种能力分开校验，服务端不能通过登录 token 推出频道密钥。频道主的成员记录才是 owner 权限的最终依据，不能凭复制管理密钥冒充另一个账号。
 
 ## 密钥与多设备
 
-账号邀请私钥保存在密码加密的保险库中，多台设备登录同一账号后解锁同一账号私钥。频道创建时生成独立随机 K 和管理密钥 A；创建者将 owner 凭据封装给自己，服务端原子存储频道、owner 成员与该账号密钥包。邀请其他账号时仅封装 member 凭据，不能交付 A。密钥包绑定 recipient、channelId 和 mode；服务端保存密文，收件账号自动领取并在本机解密。
+账号邀请私钥保存在密码加密的保险库中，多台设备登录同一账号后解锁同一账号私钥。空间创建时生成空间访问凭据，Owner 凭据与 Owner 账号密钥包由后端原子存储；它们不再加密频道内容。频道 chat/files 域密钥在浏览器生成，并通过 Owner 账号 ECDH 公钥封装；服务端保存密文，获授权成员的账号可领取并在本机解封。
 
-已加入成员的新设备只凭账号登录即可恢复频道密钥，不需要邀请者在线，不需要复制带密钥的链接。每个浏览器有独立设备登录凭据和独立频道 S；读取账号频道列表不占席位，实际打开频道才为设备加入席位。设备撤销会撤销其账号 sessions；账号频道成员身份保留，其他设备继续访问。
+已加入成员的新设备只凭账号登录即可解封账号分发给该账号的数据域密钥，不需要邀请者在线，也不需要复制带内容密钥的链接。每个浏览器有独立设备登录凭据（账号设备），成员请求凭账号 session 鉴权，不再有按空间的终端密钥或设备席位；读取账号空间列表不占成员名额。同一账号在一个空间只占一个成员名额，设备数量不受成员上限影响。设备撤销会撤销其账号 sessions；账号空间成员身份及其人数名额保留，其他设备继续访问。服务端按账号统计在线状态与设备数，成员栏只展示用户。
 
-本机记住登录保存 session token、不可导出的保险库 CryptoKey 和加密保险库，不保存密码/verifier。它允许本机用户解锁此账号；退出删除该记录。登录态与本机资源数据库在同一启动屏障后恢复，避免先加载访客资源再切换账号。
+本机记住登录保存 session token、不可导出的保险库 CryptoKey 和加密保险库。勾选记住账号密码时，将填充资料用另一把不可导出的本机 AES-GCM 密钥加密保存；不保存 verifier。退出清除自动恢复 session，保留已选择保存的填充资料，明确清除时全部移除。登录态与本机资源数据库在同一启动屏障后恢复，避免先加载访客资源再切换账号。
 
 ## 文件目录与内容
 
-thread/文件夹结构以及文件目录记录使用频道加密日志。上传文件先完成密文上传，再发布加密 file.published 目录记录，包含文件 ID、thread/folder、名称、类型、大小；成员同步目录无需下载文件内容，也不消耗下载次数。目录与文件内容中的元数据必须相互匹配，否则拒绝展示。
+频道、分组、目录和资源归属通过服务端结构接口管理，前端拉取快照并渲染。上传文件完成密文传输后提交资源归属；归属操作也保存在本机队列中，断网重试不丢失。文件名称、类型、大小继续保存在加密 file.published 元数据中，读取元数据不消耗下载次数；下载内容后校验元数据一致性。
 
-频道 K 经 HKDF 派生内容根与每文件独立 AES-GCM 密钥；保留现有逐帧认证、FINAL、连续性、padding、ID/AAD 校验与持久化密文重试。下载逐块解密到本机临时存储，完整性和大小校验成功才交付文件；出错清除临时内容。OPFS 不可用时使用 Blob 回退并明确限制。
+不迁移旧加密结构或旧账户资料，不提供导入接口。新结构与新资料直接由后端管理，客户端不再处理结构控制记录。
+
+空间访问凭据不再用于频道内容加密。每频道 chat/files 域各自生成随机 32 字节 epoch 密钥，按账号公钥封装；每个聊天条目、文件及加密发布元数据再独立生成随机对象密钥，由对应域密钥加密封装。对象封装的 AAD 绑定空间、频道、域、epoch 和 itemId。保留现有逐帧认证、FINAL、连续性、padding、ID/AAD 校验与持久化密文重试。下载逐块解密到本机临时存储，完整性和大小校验成功才交付文件；出错清除临时内容。OPFS 不可用时使用 Blob 回退并明确限制。
 
 ## 安全边界
 
-共享频道密钥意味着任何成员都能解密历史，不能通过移除成员收回其已持有的 K 或明文。当前不实现密钥 epoch 轮换或前向保密，不能声称移除成员可阻止恶意服务端向其提供将来密文。服务端成员/设备撤销负责正常服务下的访问控制。
+频道域 epoch 与随机对象密钥允许新成员按设置只领取当前 epoch，服务端也会在写入时检查作者、频道授权及当前 epoch。`WorkspaceChannel` 是唯一频道聚合；Chat 与 FileGroup 是独立域，授权和密钥隔离，但共享对象帧存储。账号设备已具备根签证书和 FINAL 对象帧签名验证基础；频道结构命令、删除事件和成员/设备撤销后的域轮换仍未完成。已获得的历史密钥和明文无法被收回，因此不能声称已实现前向保密。
 
-首次邀请公钥来自服务端目录，必须如实保留公钥替换风险；AES-GCM 认证证明密文未被未持钥者篡改，不证明具体发送账号。逐账号签名、密钥透明性与密钥轮换属于单独的协议升级，不能以补齐账号功能代替这些保证。前端代码与运行终端仍是信任根。
+账号签名根公钥和根签名设备证书已有基础实现，首次从服务端获得的其他账号根公钥使用 TOFU 固定；首次密钥替换仍无法检测。频道结构、权限、作者归属和聊天/文件生命周期目前尚未改为签名事件，客户端尚未校验 Owner Capability 或事件签名。密钥透明性、授权/事件签名和成员撤销密钥轮换仍未完成，不能宣称已抵御主动恶意服务端。前端代码与运行终端仍是信任根。
 
-账号昵称与设备名是不同概念，昵称不参与密钥派生。头像仅接受有大小上限的 PNG/JPEG/WebP，保存在加密资料中，禁止第三方头像 URL 和可执行 SVG。
+账号昵称与设备名是不同概念，昵称不参与密钥派生。头像接受有大小上限的 PNG/JPEG/WebP，由后端管理，禁止第三方头像 URL 和可执行 SVG。聊天发送者由服务端条目作者和账号资料提供，不接受加密内容中的身份声明。
 
-界面术语采用「空间 → 频道分组 → 频道 → 文件夹/聊天」。内部 Channel/Thread 命名保留，分别映射空间/频道；分组沿用加密 CONTROL 日志，不引入新的成员或密钥体系。
+界面术语采用「空间 → 频道分组 → 频道 → 文件夹/聊天」。旧资源路由 /channels 和帧协议 threadId 保留，分别映射空间/频道；新结构接口使用 /spaces。账号保险库保存私钥和访问凭据，资料与结构不再由客户端合并同步。

docs/api.md

@@ -1,6 +1,12 @@
-# API 契约 2.1
+# API 契约 6.0
 
-URL 基础路径保留 `/api/v1`，`/info.contract_version` 为 `2.1.0`。旧主版本客户端会被契约预检拒绝。创建频道/分享以及所有 owner 管理操作必须携带有效账号 session；公开链接仍允许访客按频道加入规则访问。
+账户资料使用 `GET/PATCH /accounts/profile`；头像为 PNG/JPEG/WebP data URI，禁止远程 URL 和 SVG。不提供旧资料导入。
+空间结构使用 `GET /spaces/{id}/structure`，包含 revision、channels、groups、folders、locations。频道与分组分别通过 `/spaces/{id}/channels` 和 `/spaces/{id}/groups` 创建；响应同时包含完整结构快照和服务端新建实体及 ID。其他字段通过 PATCH 重命名；频道归属通过 `PUT /spaces/{id}/channels/{channelId}/group` 修改。文件夹通过 `/spaces/{id}/folders` 创建及 PATCH 重命名，文件归属通过 `PUT /spaces/{id}/locations` 修改。
+频道、分组和目录写操作需要账号会话和空间写权限；允许上传的成员可以关联和移动自己的资源，文件移动必须满足每个条目的作者或管理权限，跨空间、跨频道的错误分组/目录关联被拒绝。结构修改后通知订阅设备重新拉取。
+
+URL 基础路径保留 `/api/v1`，`/info.contract_version` 为 `8.2.0`(8.2 新增身份组 `/spaces/{id}/roles`:结构快照多了 `roles`、`rolesSeeded`,内容事件记录多了 `signerAccount`;8.1 新增 `DELETE /spaces/{id}/groups/{groupId}`:删除分组,组内频道回到未分组)。v8 让频道强制登录：去掉未登录访客（设置 `allow_guests`、`/guests` 接口、访客终端席位），频道与空间的所有接口都要求账号会话，缺少时返回 `401 account_required`；便捷分享（`/shares`）不受影响。v7 把「设备」收束为账号的属性：成员只按用户管理，`seats` 系列命名改为 `max_members` / `members_used` / `members_full`，去掉设备名与设备清单接口，登录账号不再需要终端密钥。v6 引入账号签名根密钥、设备证书和频道对象签名事件；不兼容的旧主版本客户端会被契约预检拒绝。账号资料与空间结构由服务端管理。创建频道/分享以及所有 owner 管理操作必须携带有效账号 session；频道链接只对登录账号有效，未登录的人先登录再按加入规则加入。
+
+`GET /info` 的 `defaults` 包含 `channel`、`share` 创建设置；省略创建请求的 settings 时服务端使用相同默认值。`choices.max_members` 与 `limits.max_members` 表示成员人数范围，不代表设备数。频道设置 JSON 字段为 `max_members`（旧存储里的 `seats` 在启动时迁移）。其他选项按部署限制收束，前端只格式化选项文案，不提供替代业务默认值。
 
 基础路径 `/api/v1`。所有请求和响应的二进制数据格式见 [protocol.md](protocol.md)。前端托管在独立域名,服务端需要配置 CORS 白名单。
 
@@ -10,23 +16,24 @@ URL 基础路径保留 `/api/v1`，`/info.contract_version` 为 `2.1.0`。旧主
 |---|---|
 | `X-WD-Role` | `read` / `write` / `owner`,指明 `Authorization` 里的令牌属于哪种角色 |
 | `Authorization` | `Bearer <base64url(令牌)>` |
-| `X-WD-Endpoint` | `base64url(S)`,终端密钥,用于席位 |
+| `X-WD-Endpoint` | `base64url(S)`,终端密钥。**只用于便捷分享**(未登录的创建者与读者);频道与空间不使用,可省略 |
 | `X-WD-Cap` | 创建频道时的 Cap 验证码 token(服务端启用验证码时必填,见 protocol §11) |
 | `X-WD-Max-Downloads` | 第 0 帧上带,条目的下载上限,0 为不限 |
-| `X-WD-Account` | 账号 session token。与频道/分享的能力令牌分开；创建、管理和账号成员请求必填，访客省略 |
+| `X-WD-Account` | 账号 session token。与频道/分享的能力令牌分开；频道、空间、创建和管理请求必填 |
+| `X-WD-Event-*` | 已登记签名设备提交频道对象 FINAL 帧时必填，绑定对象 ID、域/epoch、事件类型与完整密文帧 manifest，见 protocol §21 |
 
-raw 模式的读请求不需要令牌,但仍需要 `X-WD-Endpoint`。
+raw 模式的读请求不需要令牌,但仍需要账号会话。
 
-WebSocket 无法设置头,令牌通过 `Sec-WebSocket-Protocol` 传递:`wd.v1, wd.role.<role>, wd.auth.<base64url(令牌)>, wd.ep.<base64url(S)>`,服务端回选 `wd.v1`。不要放进 URL,否则会被代理记录。
+WebSocket 无法设置头,令牌通过 `Sec-WebSocket-Protocol` 传递:`wd.v1, wd.role.<role>, wd.auth.<base64url(令牌)>, wd.account.<base64url(账号 session)>`,服务端回选 `wd.v1`。不要放进 URL,否则会被代理记录。
 
 ## 2. 权限矩阵
 
 | 操作 | 需要 |
 |---|---|
-| 读日志、拉取条目 | `read`(enc)或知道 id(raw),并占有席位 |
+| 读日志、拉取条目 | `read`(enc)或知道 id(raw),并已是该频道的成员(账号) |
 | 追加帧 | `write`(`members_can_upload` 为 true 时)或 `owner` |
-| 删除条目 | `owner`;`delete_policy=own` 时终端哈希等于条目作者;`anyone` 时任意已入席终端 |
-| 改设置、删频道、看和释放席位 | `owner`;这些管理操作不占席位 |
+| 删除条目 | `owner`;`delete_policy=own` 时账号等于条目作者;`anyone` 时任意成员 |
+| 改设置、删频道、撤销成员 | `owner`;这些管理操作不占成员名额 |
 
 ## 3. 接口
 
@@ -34,28 +41,32 @@ WebSocket 无法设置头,令牌通过 `Sec-WebSocket-Protocol` 传递:`wd.v1, w
 
 用户名为 3–32 位 ASCII 字母、数字、`_` 或 `-`，大小写不敏感。客户端 PBKDF2-SHA256（600,000 次）派生口令根，再分别派生登录凭据和 AES-GCM 保险库密钥。登录凭据仅经 HTTPS 发送；服务端再用随机 salt 和 PBKDF2-SHA256（210,000 次）存储慢哈希，数据库里的哈希不能直接用于登录。服务端不接收口令根或保险库密钥。二进制字段使用标准 Base64，保险库密文最大 1.3 MB。
 
-- `POST /api/v1/accounts` 注册 `{username,salt,verifier,vault,public_key}`。public_key 为 P-256 ECDH 公钥 JWK 的 JSON 字符串；私钥只在客户端加密保险库中保存。
+- `POST /api/v1/accounts` 注册 `{username,salt,verifier,vault,public_key,signing_public_key}`。`public_key` 是 P-256 ECDH 公钥，`signing_public_key` 是 P-256 ECDSA 账号根公钥；对应私钥只保存在客户端加密保险库中。API v6 不兼容旧账号保险库协议，不自动迁移旧签名身份。
 - `POST /api/v1/accounts/salt` 请求 `{username}`，返回 `{salt}`，供客户端派生登录凭据。
 - `POST /api/v1/accounts/session` 请求 `{username,verifier,device_id?,device_name?}`。成功返回 `{username,token}`；session token 随机生成，只保存 SHA-256，期限 30 天。
 - `GET /api/v1/accounts/vault` 使用 `Authorization: Bearer <token>` 读取 `{revision,vault}`。
 - `PUT /api/v1/accounts/vault` 使用同一鉴权，发送 `{revision,vault}`。revision 乐观并发控制；冲突返回 `409 vault_conflict`，客户端必须先读取并合并，不能静默覆盖。
 - `DELETE /api/v1/accounts/session` 撤销当前 bearer session；退出登录时调用。
-- `GET /api/v1/accounts/users/{username}/key` 已登录用户查询收件账号公开邀请密钥。
+- `GET /api/v1/accounts/users/{username}/key` 已登录用户查询 ECDH 邀请公钥和可选的账号签名根公钥。
+- `PUT /api/v1/accounts/devices/signing-key` 当前设备提交 `{device_id,public_key,signature}`。服务端核对账号 session 绑定的 device_id，并验证账号根密钥对 P-256 设备公钥证书的签名后保存。
+- `GET /api/v1/accounts/users/{username}/key` 返回账号 ECDH 公钥与签名根公钥；签名对象携带设备公钥和根签设备证书，客户端首次 TOFU 固定根公钥后离线验设备证书。
 - `GET /api/v1/accounts/invitations` 返回当前账号的邀请，payload 为绑定收件用户名和频道 ID 的 ECDH + HKDF + AES-GCM 密文。
 
 没有邮箱找回流程。忘记密码后保险库无法恢复。保险库仅同步资源凭据和草稿清单，不同步设备 S、设备名、缓存、原始文件或发送队列。浏览器存储按账号与访客分库；切换账号会中止订阅并清空内存会话。资源清单移除使用带时间戳的墓碑同步，避免旧设备将条目恢复。
 
+签名根密钥保存在加密保险库；设备签名私钥以不可导出的 CryptoKey 保存在本机账户数据库，不随保险库同步。已登记签名设备写入 Workspace 对象时，FINAL 帧和删除请求必须带签名事件；尚未把签名要求扩展到频道结构和成员/权限变更。
+
 ### `GET /api/v1/info`
-返回服务端能力:协议版本、限制、验证码配置(`captcha.provider`、`captcha.enabled`、`captcha.api_endpoint`,即 Cap widget 要连接的地址)、传输能力。验证码的 secret 不会出现在这里。`transports.http3` 只是部署层(反向代理或 Kestrel 配置)声明已启用 HTTP/3,服务端进程本身不内置 QUIC。
+返回服务端能力:协议版本、限制、验证码配置(`captcha.provider`、`captcha.enabled`、`captcha.api_endpoint`,即 Cap widget 要连接的地址)、传输能力以及创建默认值/选项。`limits.max_workspace_bytes` 是单个空间全部资源的上限，`limits.max_workspace_channel_bytes` 是单个频道 Files 域的文件容量上限；频道结构的 `fileBytes` 为当前已用容量。前端只展示服务端返回的用量和限制。`defaults.channel_mode`、`defaults.channel` 和 `choices` 是前端创建表单的初始值与可选项；服务端独立校验提交的设置。验证码的 secret 不会出现在这里。`transports.http3` 只是部署层(反向代理或 Kestrel 配置)声明已启用 HTTP/3,服务端进程本身不内置 QUIC。
 
 ### `POST /api/v1/channels`
-创建者必须登录。只有一套频道/成员/线程模型，`mode=enc|raw` 仅决定客户端内容是否端到端加密，不改变业务权限。创建者自动写入该频道的 owner 成员记录并占一个设备席位。服务端启用验证码时还需要 `X-WD-Cap`。
+创建者必须登录。创建请求必须提供 `settings.name`，服务端拒绝缺失、空白或纯空格名称并返回 `400 space_name_required`，存储时去除首尾空格；名称长度最多 48 个字符。只有一套频道/成员/线程模型，`mode=enc|raw` 仅决定客户端内容是否端到端加密，不改变业务权限。创建者自动写入 owner 成员记录并占一个成员名额，同时登记当前设备终端；该账号的其他设备不增加名额。服务端启用验证码时还需要 `X-WD-Cap`。
 
 ```json
 {
   "id": "<channel_id>",
   "mode": "enc",
-  "settings": { "name": "工作设备", "seats": 2, "members_can_upload": true, "delete_policy": "own",
+  "settings": { "name": "项目组", "max_members": 2, "members_can_upload": true, "delete_policy": "own",
                 "ttl_seconds": 86400, "max_items": 1000, "file_max_downloads": 10 },
   "read_hash": "<sha256(T_read)>",
   "write_hash": "<sha256(T_write)>",
@@ -63,35 +74,35 @@ WebSocket 无法设置头,令牌通过 `Sec-WebSocket-Protocol` 传递:`wd.v1, w
 }
 ```
 
-raw 模式省略 `read_hash`;`write_hash` 仅在成员可上传时提供。创建者的终端(`X-WD-Endpoint`)自动入席。返回 `201`,响应体与「读取频道信息」相同(`ChannelInfo`)。
+raw 模式省略 `read_hash`;`write_hash` 仅在成员可上传时提供。创建者自动成为频道的所有者成员。返回 `201`,响应体与「读取频道信息」相同(`ChannelInfo`)。
 
 ### `GET /api/v1/channels/{id}`
-返回 `ChannelInfo`:设置(包含所有成员共享的频道名)、模式、席位占用、`oldest_seq`、`last_seq`、时间。**不占席位**,任意角色可调用,用于加入前预览和核对模式。频道名是普通设置,服务端可见。
+返回 `ChannelInfo`:设置(包含所有成员共享的频道名)、模式、成员名额占用(`members_used`)、`oldest_seq`、`last_seq`、时间。`members_used` 统计唯一账号成员，不统计账号的设备数。**不占成员名额**,需要账号会话,用于加入前预览和核对模式。频道名是普通设置,服务端可见。
 
-### `POST /api/v1/channels/{id}/seats`
-加入频道,占用一个席位。幂等:同一终端重复调用返回同一席位。席位已满返回 `403 seats_full`。读取频道信息和 owner 管理接口不占席位;频道内容、席位信息/设备名等其余操作要求终端已入席,否则返回 `403 not_joined`。
+### `POST /api/v1/channels/{id}/join`
+加入频道，必须带账号会话（没有则 `401 account_required`）。只登记成员关系：账号第一次加入时占一个成员名额，同一账号的更多设备不增加名额，此后仅凭账号会话鉴权。同一账号重复调用幂等。成员名额已满时返回 `403 members_full`。读取频道信息和 owner 管理接口不占成员名额；访问频道内容前必须已加入，否则返回 `403 not_joined`。响应 `JoinResult`：`{joined_at, members_used, members_max}`，不再返回终端标识。
 
-可发送 JSON `{password}`。默认 `join_policy=open,allow_guests=true`，允许持链接的陌生人设备加入。`allow_guests=false` 要求账号登录；`join_policy=invite` 要求该账号已受邀。频道主、已加入的账号成员和受邀账号无需再次输入频道密码。密码由服务端保存加盐 PBKDF2 哈希，从不通过频道信息返回。成员账号和设备身份独立：同一账号可占多个独立设备席位；账号成员的读写请求必须出示对应账号 session 和该设备 S。
+可发送 JSON `{password}`。`join_policy=open` 允许持链接的登录账号加入；`join_policy=invite` 要求该账号已受邀。频道主、已加入的账号成员和受邀账号无需再次输入频道密码。密码由服务端保存加盐 PBKDF2 哈希，从不通过频道信息返回。设备是账号的属性：同一账号可在任意多台设备登录，只占一个成员名额；账号成员的读写请求出示有效账号 session 即可，不再绑定到某个终端。
 
-`GET /channels/{id}/members` 返回频道内账号成员及 `owner|member` 角色。`GET/POST /channels/{id}/invitations` 由频道主查询/发送 `{username,payload}` 邀请；payload 只含客户端加密的成员链接。`DELETE /channels/{id}/invitations/{username}` 撤销邀请、成员授权与该账号的设备席位，并阻止重新加入，直到再次邀请。不能移除频道主。设备面板踢出访客也会阻止该 S 重新加入。
+`GET /channels/{id}/members` 返回频道内账号成员及 `owner|member` 角色，每项附带账号级 `online`（该账号在本频道有活动 WebSocket/SSE 订阅）、`devices`（该账号的登录设备数，不小于 `online_devices`）与 `online_devices`（该账号此刻在本频道有订阅的设备数）；设备是账号的属性，不单独作为成员。在线状态只来自内存里的订阅登记，不写库、不经订阅流推送，客户端按需轮询。`GET /channels/{id}/invitations` 不再返回已经成为成员的账号。邀请前，频道主调用 `GET /channels/{id}/invitations/{username}/crypto-plan` 获取服务端根据成员权限和历史设置计算的域/epoch/收件人计划。浏览器只为计划中的收件人生成并封装域密钥；随后 `POST /channels/{id}/invitations` 原子提交账号链接包与 `domain_envelopes`。服务端会重新计算计划并校验每个 epoch 和收件人，不接受前端自行增加授权或选择轮换范围。`DELETE /channels/{id}/invitations/{username}` 撤销邀请、成员授权与域密钥包，并阻止重新加入，直到再次邀请。不能移除频道主。移除访客用 `DELETE /channels/{id}/guests/{endpoint_hash}`，同样阻止该终端重新加入。
 
-频道设置、成员权限、邀请、加入密码与加密模式统一作用于同一 Channel。每次上传、发言、线程/目录控制条目写入均经服务器校验账号或访客设备、频道成员/席位与写入权限，不能靠客户端隐藏按钮绕过。WebSocket 账号 session 经 `wd.account.<base64url(token)>` 子协议传递，并在推送循环中重新检查有效性。
+频道设置、成员权限、邀请、加入密码与加密模式统一作用于同一 Channel。每次上传、发言、线程/目录控制条目写入均经服务器校验账号会话、频道成员关系与写入权限，不能靠客户端隐藏按钮绕过。移除账号成员才会释放成员名额；撤销账号的某台登录设备只使该设备的会话失效，不影响成员身份。WebSocket 账号 session 经 `wd.account.<base64url(token)>` 子协议传递，并在推送循环中重新检查有效性。
 
 ### `PATCH /api/v1/channels/{id}/settings`
-所有者修改设置。可通过 `name` 更新共享频道名,传空字符串清除名称;`ttl_seconds` 的修改从现在起算。
+所有者修改设置。可通过 `name` 更新共享频道名,传空字符串清除名称;`max_members` 调整成员人数上限，不能改变已有成员身份;`ttl_seconds` 的修改从现在起算。
 
 ### `DELETE /api/v1/channels/{id}`
 所有者删除整个频道和全部密文。
 
 ### `POST /api/v1/channels/{id}/frames`
-追加一帧。请求体是完整封装(`application/octet-stream`)。
+追加一帧。请求体是完整封装(`application/octet-stream`)。当账号设备已登记签名证书且对象在 `/spaces/{id}/crypto/objects` 声明时，最终帧必须携带 `X-WD-Event-Id/Kind/Channel/Domain/Epoch/Frames/Manifest/Signature`（编辑可带 `X-WD-Event-Target`）。服务端验签并核对此前帧摘要与当前 FINAL 帧的清单；缺少或无效签名拒绝提交。签名随对象元数据进入 `CryptoState`，成员读取时仍按数据域权限过滤。
 
 | 响应 | 含义 |
 |---|---|
 | `201 {"seq"}` | 新追加 |
 | `200 {"seq"}` | 幂等重发,返回原 seq |
 | `409` | 同一 `(item_id, frame_index)` 内容不同 |
-| `403` | 无权、席位已满、模式或 ENC 标志不符 |
+| `403` | 无权、成员人数已满、模式或 ENC 标志不符 |
 | `413` | 超出限制 |
 | `429` | 限流 |
 
@@ -101,7 +112,7 @@ raw 模式省略 `read_hash`;`write_hash` 仅在成员可上传时提供。创
 ### `GET /api/v1/channels/{id}/ws?from=<seq>`
 WebSocket 订阅(降级链的第一级)。服务端向下推送:
 - 二进制消息:一条日志记录。
-- 文本消息(JSON 控制消息):`{"t":"hb","seq":N}` 心跳,`{"t":"settings"}` 设置变更,`{"t":"seats"}` 席位变更。
+- 文本消息(JSON 控制消息):`{"t":"hb","seq":N}` 心跳,`{"t":"settings"}` 设置变更,`{"t":"members"}` 成员变更。
 
 上传仍走 HTTP `POST`,便于幂等重试。
 
@@ -112,20 +123,18 @@ SSE 订阅(降级链的第二级)。记录以 base64url 放在 `data:` 中,`id:`
 WebSocket → SSE → 长轮询,每一级失败自动降级。心跳间隔 20 秒,45 秒收不到任何消息即判定死链。重连使用指数退避(1 秒到 30 秒)加抖动,并携带 `from=last_seq+1`。
 
 ### `GET /api/v1/channels/{id}/items/{item_id}/frames?from=<index>`
-拉取条目的帧(GATED 条目的取数方式)。`from=0` 计一次下载;`from>0` 只有同一终端此前对同一条目成功启动过 `from=0` 才能续传,否则返回 `410 gone`。条目尚未 FINAL 时,响应会随帧到达持续输出,直到 FINAL。达到下载上限后返回 `410`,并在 5 分钟宽限期后删除密文,宽限期内已开始的拉取可继续续传。
+拉取条目的帧(GATED 条目的取数方式)。`from=0` 计一次下载;`from>0` 只有同一下载方（按用户）此前对同一条目成功启动过 `from=0` 才能续传,否则返回 `410 gone`。条目尚未 FINAL 时,响应会随帧到达持续输出,直到 FINAL。达到下载上限后返回 `410`,并在 5 分钟宽限期后删除密文,宽限期内已开始的拉取可继续续传。
 
 ### `DELETE /api/v1/channels/{id}/items/{item_id}`
-按 `delete_policy` 授权后删除条目,并在日志中追加 tombstone。
+按 `delete_policy` 授权后删除条目,并在日志中追加 tombstone。已登记签名设备还必须提交对应 `chat.delete`/`file.delete` 事件头；服务端验证其绑定的设备证书、权限和原对象帧 manifest 后保存删除签名，浏览器验签后才应用 tombstone。
 
-### 席位
-- `GET /api/v1/channels/{id}/seats`:所有者查看(终端哈希、加密设备名、加入时间)。
-- `PUT /api/v1/channels/{id}/seats/me`:终端上传设备名(≤256 B);enc 模式加密,raw 模式明文。
-- `PUT /api/v1/channels/{id}/seats/{endpoint_hash}/label`:所有者为指定设备更新名称;enc 模式的密文绑定目标 endpoint hash,raw 模式明文。设备也可用 `/seats/me` 更新自己的名称。
-- `DELETE /api/v1/channels/{id}/seats/{endpoint_hash}`:所有者移除该设备的席位,其活动订阅随后会被拒绝。
+### 已移除的接口
+- v8:`GET /channels/{id}/guests`、`DELETE /channels/{id}/guests/{endpoint_hash}`(频道不再有未登录访客;成员按用户管理:`/members`、`/invitations`)。
+- v7:`PUT /channels/{id}/seats/me`、`PUT /channels/{id}/seats/{endpoint_hash}/label`、`GET/DELETE /channels/{id}/seats`。设备名只在账号设备管理里存在(`/accounts/devices`)。
 
 ## 4. 便捷分享接口
 
-便捷分享是与频道并列的另一种资源,语义见 [protocol.md §15](protocol.md)。**没有 WebSocket、SSE、日志、席位和成员上传**。接口前缀 `/api/v1/shares`,只支持 enc 模式,鉴权头只用 `read` 和 `owner` 两种角色(`write` 会被拒绝为 `bad_request`)。
+便捷分享是与频道并列的另一种资源,语义见 [protocol.md §15](protocol.md)。**没有 WebSocket、SSE、日志、成员登记和成员上传**。接口前缀 `/api/v1/shares`,只支持 enc 模式,鉴权头只用 `read` 和 `owner` 两种角色(`write` 会被拒绝为 `bad_request`)。
 
 | 接口 | 角色 | 阶段 | 说明 |
 |---|---|---|---|
@@ -200,11 +209,12 @@ WebSocket → SSE → 长轮询,每一级失败自动降级。心跳间隔 20
 |---|---|---|
 | `bad_request` | 400 | 封装格式或参数错误 |
 | `unauthorized` | 401 | 令牌缺失或错误 |
+| `account_required` | 401 | 需要账号会话:频道与空间只接受已登录账号,账号会话缺失或已失效 |
 | `forbidden` | 403 | 角色不够 |
-| `not_joined` | 403 | 终端未入席,或席位已被所有者释放 |
+| `not_joined` | 403 | 账号不是该频道成员(未加入或已被所有者移除) |
 | `visitors_full` | 403 | 便捷分享的访客名额已满,且这个终端未登记 |
 | `sealed` | 409 | 便捷分享已封存,不能再修改;封存后再用所有者令牌发请求也是这个错误 |
-| `seats_full` | 403 | 席位已满 |
+| `members_full` | 403 | 成员人数已满 |
 | `mode_mismatch` | 403 | 帧的 ENC 标志与频道模式不符 |
 | `not_found` | 404 | 频道或条目不存在,或已过期 |
 | `conflict` | 409 | 幂等冲突 |
@@ -216,12 +226,12 @@ WebSocket → SSE → 长轮询,每一级失败自动降级。心跳间隔 20
 
 ### 按账号恢复频道密钥
 
-- `GET /api/v1/accounts/channels`：只需 `X-WD-Account`，返回当前账号已加入频道的 `{channel_id,role,payload,created_at}` 密钥包；不返回其他账号或未接受邀请的密钥包，不占席位。
+- `GET /api/v1/accounts/channels`：只需 `X-WD-Account`，返回当前账号已加入频道的 `{channel_id,role,payload,created_at}` 密钥包；不返回其他账号或未接受邀请的密钥包，不占成员名额。
 - `PUT /api/v1/channels/{id}/key-package`：需要该频道 owner 能力和 owner 账号，仅更新当前 owner 自己的 `{payload}`，用于补齐已创建频道的账号密钥包。
 - 创建频道可携带 `key_package`（1–16384 字符 opaque 密文），与频道和 owner 成员记录原子保存。前端必须提供；底层 API 允许省略供纯协议客户端使用。
-- 发送邀请时原子保存收件账号的密钥包；接受后仍可跨设备领取。撤销邀请/成员同时删除密钥包，删除频道清理全部密钥包。
+- 发送邀请时原子保存收件账号的空间密钥包、频道数据域 envelopes、默认权限和 epoch 更新；接受后仍可跨设备领取。撤销邀请/成员会删除服务端密钥包与访问记录，但无法收回对方此前保存的密钥，成员移除后的 epoch 轮换仍未实现。删除空间时清理全部密钥包。
 
 
 ### 账号设备与资料
 
-GET /accounts/devices 返回本账号设备 {id,name,created_at,last_seen,current}。PATCH /accounts/devices/{id} 发送 {name}；DELETE 撤销该设备全部登录 sessions 与频道席位，不移除账号成员。新客户端登录时携带稳定浏览器 device_id（UUID）和设备名，各设备单独记录。个人名称/头像存储在客户端加密保险库，修改后按 modifiedAt 合并，不写入服务端明文账号表。昵称不改变固定用户名或参与密钥派生。
+GET /accounts/devices 返回本账号设备 {id,name,created_at,last_seen,current}。PATCH /accounts/devices/{id} 发送 {name}；DELETE 撤销该设备的全部登录 sessions，不移除账号成员。新客户端登录时携带稳定浏览器 device_id（UUID）和设备名，各设备单独记录。个人名称/头像存储在客户端加密保险库，修改后按 modifiedAt 合并，不写入服务端明文账号表。昵称不改变固定用户名或参与密钥派生。

docs/architecture.md

@@ -1,5 +1,13 @@
 # 架构
 
+公共业务数据（空间设置、成员、设备、邀请、默认值和部署限制）由后端 DTO 和服务端响应定义；前端类型由构建工具生成。本地资源保险库只携带访问凭据与离线副本，不覆盖在线响应中的设置。在线刷新不改变资源的用户修改时间，也不产生删除标记；只在网络故障时回退缓存。
+
+账户昵称头像、空间、频道、分组、文件夹和文件归属由后端管理。空间结构变更经服务端验证关联和权限后持久化，再通知设备重新拉取。新空间和初始“常规”频道在一个事务中创建。
+
+消息、文件内容和文件名称等资源元数据由客户端加密，后端保存密文和加密密钥包。账号保险库保存解密凭据，不再作为个人资料或空间结构的数据源。
+
+不提供旧数据迁移或导入接口。新空间结构由后端直接创建和管理，客户端不解码或重放旧结构控制记录。
+
 ## 1. 组件
 
 账号、设备、频道、thread 与内容加密的统一边界见 [account-channel-architecture.md](account-channel-architecture.md)。该文档明确账号成员与设备会话分离、按账号领取频道密钥包及加密文件目录。
@@ -69,7 +77,7 @@ SQLite 存元数据和小帧,磁盘存大帧。
 | `channel_join_denials` | 被移除的账号或设备标识，再次邀请账号时清除账号禁入 |
 | `accounts/account_sessions` | 登录 salt、登录凭据慢哈希及独立 salt、邀请公钥、保险库密文/revision；随机 session token 的 SHA-256 与过期时间 |
 | `shares` | `id` PK(与频道共用全局 id 空间), `settings`(JSON), `read_hash`, `owner_hash`(封存时清空), `creator_endpoint_hash`, `created_at`, `expires_at`, `sealed_at`, `manifest_item_id`, `bytes` |
-| `seats` | `channel_id`, `endpoint_hash`, `label` BLOB, `joined_at`;PK(`channel_id`, `endpoint_hash`) |
+| `channel_members` | 频道成员(账号):`channel_id`, `username`, `role`, `joined_at`。v8 起不再有访客席位,旧库里的 `seats` 表在启动时丢弃 |
 | `share_visitors` | `share_id`, `endpoint_hash`, `joined_at`;PK(`share_id`, `endpoint_hash`),创建者终端不写入此表 |
 | `items` | `channel_id`, `item_id`, `author_hash`, `flags`, `max_downloads`, `downloads`, `frame_count`, `max_index`, `final_index`, `bytes`, `created_at`, `expires_at`, `close_deadline`, `label`;PK(`channel_id`, `item_id`)。完整与否由 `final_index` 和 `frame_count` 推出,是否进入宽限期由 `close_deadline` 表示 |
 | `share_items` | 分享条目的帧状态和下载次数,独立于频道条目 |
@@ -86,7 +94,7 @@ SQLite 存元数据和小帧,磁盘存大帧。
 
 **并发模型**:写入由单个 SQLite 连接加锁串行执行(WAL 模式),读取使用独立连接,每次 `Read` 在显式事务里,看到一致的快照。订阅枢纽 `ChannelHub` 只传递「有变化」的信号,订阅者被唤醒后自己按游标读日志,所以不存在回放与实时之间漏帧的竞态,也无需为慢客户端缓冲数据。代价是目前只支持**单实例**部署。
 
-便捷分享与频道共用 ID 唯一性检查,但条目和帧使用独立表。分享不创建席位或日志;封存时在单个事务里清空 `owner_hash`、记录清单 id 并启动 TTL。
+便捷分享与频道共用 ID 唯一性检查,但条目和帧使用独立表。分享不登记成员或日志;封存时在单个事务里清空 `owner_hash`、记录清单 id 并启动 TTL。
 
 后台服务每 30 秒清理:过期条目、下载达上限且宽限期已过的条目、过期频道,每次产生对应的墓碑并删除密文;每 20 轮额外清理超过 10 分钟的孤立 blob。超出 `max_items` 的淘汰和新快照取代旧快照,在追加时同步完成。
 
@@ -106,9 +114,9 @@ SQLite 存元数据和小帧,磁盘存大帧。
 - 发送队列落在 IndexedDB,恢复网络后自动补发,依赖协议的幂等追加。
 - 条目预览在沙箱 iframe 中渲染;raw 内容只当文本展示或下载。
 - 下载大文件优先使用 OPFS 流式写入临时文件，认证完成后提供文件；不支持 OPFS 时回退 Blob，限制 64 MiB。
-- 首页先注册/登录；公开频道/分享链接可按规则由访客访问。创建与管理在服务端绑定账号，频道内成员角色与设备席位分开。所有写入都检查账号或访客设备、频道角色/席位和能力权限。
-- IndexedDB 按账号与访客分库；切换时中止后台订阅并清空内存。保险库只同步资源凭据、草稿清单和移除墓碑；设备 S、设备标签、缓存、原始文件和 outbox 保留在本机。新设备生成独立 S 后重新加入。
-- 一个 Channel/Thread 模型共用日志、权限与生命周期；内容是否端到端加密只切换客户端封装加解密。结构 CONTROL 记录不按普通内容 TTL/max_items 清理，随频道删除。
+- 首页先注册/登录；频道链接只对登录账号有效（未登录先登录），便捷分享链接任何人可读。创建与管理在服务端绑定账号，成员人数按账号去重，设备只是账号的属性（账号设备与登录 session 在 `/accounts/devices` 管理）。所有频道写入都检查账号会话、频道角色、成员名额和能力权限。
+- IndexedDB 按账号分库；切换时中止后台订阅并清空内存。保险库同步私钥、资源凭据和移除墓碑；设备 S、设备标签、草稿内容、缓存、原始文件和 outbox 保留本机。新设备生成独立 S 后重新加入。
+- 空间统一管理成员、权限与密钥，后端管理频道、分组和目录。资源日志仅保存内容及资源元数据；CONTROL 资源元数据记录随空间删除。
 
 ## 7. 阶段划分
 
@@ -116,22 +124,22 @@ SQLite 存元数据和小帧,磁盘存大帧。
 |---|---|---|
 | 0 | 文档、`test-vectors/` | 向量由独立脚本生成并人工复核 |
 | 1 | `@webdrop/core`:密钥派生、封装、加解密、padding、条目装配 | **已完成**:Vitest 通过全部向量和负例,并对着真实服务端端到端通过 |
-| 2 | 服务端(AOT):频道与便捷分享、帧存储、频道日志、WebSocket/SSE/长轮询、席位、访客名额、清理 | xUnit 通过;目标平台 AOT 发布并冒烟通过 |
+| 2 | 服务端(AOT):频道与便捷分享、帧存储、频道日志、WebSocket/SSE/长轮询、成员、在线状态、便捷分享访客名额、清理 | xUnit 通过;目标平台 AOT 发布并冒烟通过 |
 | 3 | 前端:创建频道、文本和 JSON 实时同步、断线重连、发送队列、「我的频道」 | Playwright:双浏览器内容一致,断网恢复后无丢失无重复,抓包无明文和 K |
 | 4 | 文件:流式加解密、GATED 拉取、下载计数、预览、粘贴和拖拽 | 100 MB 文件往返一致,下载计数正确 |
 | 5 | GB 级文件:并行上传和断点续传 | 中途断网后续传成功,内存占用平稳 |
 | 6 | PWA、Web Share Target、二维码和短配对码(PAKE) | 手机端走通 |
 | 7 | 账号登录、客户端加密资源保险库 | 已实现客户端派生口令 verifier/保险库密钥、SQLite opaque vault、资源同步;口令丢失时明确告知无法恢复 |
-| 8 | thread、虚拟文件夹与 IRC 风格聊天 | 已实现沿用频道加密日志,消息按 thread 归属并展示发送设备,文件夹元数据由客户端加密 |
+| 8 | 空间、频道、分组、文件夹与聊天 | 结构和作者归属由后端管理，客户端加解密资源并渲染后端快照 |
 
 每个阶段开始前,先更新 protocol.md 和测试向量,再改代码。
 
 ## 8. 验收时的检查清单
 
 - `dotnet test`、`vitest`、Playwright 全部通过。
-- 对 SQLite 文件和 blob 目录 grep 明文关键字,必须查不到。
+- 对 SQLite 文件和 blob 目录检查资源内容与文件名明文关键字，必须查不到；账号资料和业务结构按设计对后端可见。
 - 服务端日志中没有 K、令牌和频道 id 明文。
-- 抓包确认请求里没有 K 和明文。
+- 抓包确认资源上传请求不包含 K 或资源明文；账户资料和结构请求使用后端业务接口。
 - AOT 发布产物能在没有 .NET 运行时的机器上运行。
 
-界面术语采用「空间 → 频道分组 → 频道 → 文件夹/聊天」。内部 Channel/Thread 命名保留，分别映射空间/频道；分组沿用加密 CONTROL 日志，不引入新的成员或密钥体系。
+界面术语采用「空间 → 频道分组 → 频道 → 文件夹/聊天」。内部资源 Channel 与帧元数据 threadId 保留，分别映射空间/频道；分组和目录由后端结构接口管理，不引入新密钥体系。

docs/deployment.md

@@ -28,6 +28,20 @@ systemctl --user start webdrop.service
 
 本机开发前端仍可运行 `cd web && npm run dev`,Vite 会代理 `/api/v1` 到本地 API。公网部署时,在 API 前配置 HTTPS 反向代理;不要把未加密 HTTP 直接暴露到公网。只有当 API 端口仅能由可信代理访问时,才信任 forwarded headers。
 
+### 开发时测上传速度
+
+经 Vite 开发代理(`npm run dev` 默认)转发上传,速度上限约 20–25 MB/s,这是 Node 代理的限制,和应用本身无关。要测到真实速度,让前端直连后端:
+
+```sh
+# 后端:允许前端所在的来源跨域(端口按实际的前端端口填)
+WebDrop__CorsOrigins__0=http://127.0.0.1:5173 ASPNETCORE_URLS=http://127.0.0.1:5000 dotnet run --project server/src/WebDrop.Api --no-launch-profile
+
+# 前端:把 API 指向后端,不走代理
+cd web && VITE_WEBDROP_API_URL=http://127.0.0.1:5000/api/v1 npm run dev
+```
+
+本机实测直连约 90 MB/s(300 MB 随机文件 3.3 秒)。上传帧的限流和普通接口分开计数(`WebDrop:FrameRequestsPerMinute`,默认 6000/分钟),上传请求体用 Blob 发送(浏览器对字节数组请求体要多拷贝几次,会慢 5 倍以上)。
+
 ## 其他 Linux 主机
 
 构建 OCI 镜像:

docs/e2ee-boundary-comparison.md

@@ -0,0 +1,116 @@
+# E2EE 协作架构边界对照
+
+对照来源：用户提供的 `D:/Users/JustMe/Downloads/E2EE_Collaboration_Architecture.md`。
+核查对象：2026-10-13 当前工作区代码，包含尚未提交、尚未部署的后端业务模型改造。此次对照不修改密钥协议，不迁移旧数据。
+
+## 判断
+
+当前实现已推进为“后端管理业务结构和访问策略、浏览器持有频道数据域密钥并加解密资源”的模型。
+参考文档是“后端协调存储、客户端验证授权”的设备身份、频道数据域和 epoch 模型。
+两者的主要差距在身份可信来源、密钥分发粒度、授权验证和撤销后的密码学隔离，而非 CRUD 或界面布局。
+
+## 对照
+
+| 边界 | 参考文档 | 当前代码 | 判断 |
+|---|---|---|---|
+| 业务结构 | 后端提供 Identity、Space、Channel、Chat、File、Sync 模块 | 账户资料、空间成员、频道、分组、目录、文件归属已放到后端，前端接口类型从 DTO 生成 | 模块方向一致 |
+| 资源加密 | 设备加密，服务端保存密文 | Worker + WebCrypto，AES-GCM 分帧，AAD/ID/FINAL/大小校验，持久化密文重试 | 可沿用基础能力 |
+| 密码与数据密钥 | 账户认证不直接充当数据加密根 | 密码/可用的 Passkey PRF 解锁保险库；随机账号 ECDH 私钥解开账号 Key Envelope；频道数据域密钥独立随机生成 | 密码不直接生成资源密钥；账号恢复仍与 E2EE 身份私钥恢复耦合 |
+| 用户身份 | Signing Identity 与 Device Keys | 账号保险库保存 P-256 签名根密钥；本机保存不可导出的设备签名私钥，根签名设备证书由后端校验并登记 | 身份密钥基础已落地；尚未用于业务事件 |
+| 新设备 | 可信恢复或已有设备审批 | 用户已决定不要求旧设备审批；新设备以账号密码/支持的 Passkey PRF 解锁同一保险库私钥 | 与参考文档的设备审批模型不同；账号被攻破会暴露该账号全部空间密钥 |
+| 设备分发 | 每个获授权设备各有 Key Envelope | 按 username 分发；设备只有 UUID 和 session（v7 起不再有按空间的席位或终端密钥，访客除外），没有设备解包公钥 | 分发对象不同 |
+| Space | 主要是授权管理范围 | 成员、频道目录、日志与同步边界；不再作为频道内容根 | 业务边界已收束，仍由服务端定义 |
+| Channel | Chat 与 FileGroup 有独立数据域和密钥 | 每频道独立 chat/files 随机 epoch key；对象另有随机 key，由域密钥封装 | 数据域已落地，密钥包仍按账号而非设备 |
+| 授权链 | Owner 签名 Capability，客户端验证 | owner/member + bearer 能力令牌 + 服务端成员表，客户端没有验证签名授权链 | 服务端仍是授权判断的信任方 |
+| 管理与读取 | Admin 可以只管理而没有解密权限 | 没有 Admin Capability；Owner 管理凭据与频道数据域密钥格式分开，但 Owner 同时能管理并读取其已授权频道 | 仍缺管理授权与数据读取权限分离 |
+| 细分权限 | 按频道、聊天/文件域授予 read/write/upload 等权限 | 默认频道权限、历史策略、epoch 与收件人计划由后端计算；邀请提交时原子校验域密钥包集合，日志、对象下载和写入按权限检查 | 初始权限和邀请策略已落地；其他频道授权 UI 和成员撤销后的轮换待补 |
+| Epoch | 成员或设备撤销触发新 epoch，排除被撤销者 | Owner 关闭新成员历史时，邀请流程按 chat/files 分别轮换 epoch；服务端拒绝旧 epoch 写入 | 新成员历史隔离已实现；成员撤销后轮换、并发与离线恢复未实现 |
+| FileKey | 每文件随机 FileKey，由 FileGroupKey 封装 | 每条目（文件、消息、加密元数据）独立随机对象密钥，由对应频道域 epoch key 封装 | 已具备独立重封装基础，批量 rewrap/撤销流程未做 |
+| 消息事件 | 已签名的 create/edit/delete/reaction，客户端 reduce | 完整对象的最终帧经账号设备签名并绑定密文 manifest；编辑是签名新对象后再删除旧对象，删除/频道结构命令尚无签名事件 | 创建/发布事件基础已接入，删除和结构授权仍缺 |
+| 作者证明 | 消息签名绑定用户/设备 | 后端 AuthorAccount 与账号资料决定显示身份 | 能提供正常服务下的身份归属，不能抵抗恶意服务端改写 |
+| 前端业务缓存 | 后端定义账户、空间、频道、权限及 API 契约 | DTO 从后端生成；IndexedDB `SavedResource` 仍缓存服务端设置/角色与本机凭据，在线发送不再根据缓存上传开关授权 | 服务端是在线权限来源；本地快照仍需与密钥/队列拆分 |
+| 存储部署 | PostgreSQL、Redis、S3 | SQLite、本机 blob、进程内 ChannelHub；NativeAOT + WebSocket/SSE/HTTP 已有 | 部署规模不同，不是首要密码学差距 |
+
+已收回后端的有：邀请/历史授权计划、默认访问权限、epoch 选择与域密钥包原子提交；上传权限不再读取本地 `membersCanUpload` 缓存；频道/分组创建直接返回服务端生成的实体 ID；`chat/files` 与 `open/invite` 已由后端枚举定义并生成前端联合类型。
+
+## 关键代码依据
+
+1. [accountCrypto.ts](../web/src/core-bridge/worker/accountCrypto.ts)：密码派生登录 verifier 和保险库密钥；账号保险库另含 ECDSA P-256 根签名密钥。`generateInvitationKeys()` 仍专用于 ECDH 邀请。
+2. [account.ts](../web/src/core-bridge/worker/account.ts)、[accountChannels.ts](../web/src/core-bridge/worker/accountChannels.ts)：新设备登录后恢复同一账号私钥，按账号领取空间授权包。
+3. [SqliteAccountStore.cs](../server/src/WebDrop.Storage/SqliteAccountStore.cs)、[SqliteAccountSigning.cs](../server/src/WebDrop.Storage/SqliteAccountSigning.cs)：账号保存根签名公钥，设备目录保存根签名证书；尚无设备解包公钥/旧设备审批。
+4. [domainCrypto.ts](../web/src/core-bridge/worker/domainCrypto.ts)、[channelDataKeys.ts](../web/src/core-bridge/worker/channelDataKeys.ts)：频道 chat/files epoch key 与随机对象 key 在客户端生成，账号 ECDH envelope 与对象封装也在客户端执行。`packages/core/kdf.ts` 仍服务于访问凭据和独立 Share/旧资源路径，不是新 Workspace 的内容密钥路径。
+5. [ChannelWorkspace.cs](../server/src/WebDrop.Core/ChannelWorkspace.cs)：后端创建频道、分组、目录并校验资源归属；`WorkspaceChannel` 保存 chat/files epoch 与新成员历史策略。
+6. [ChannelCrypto.cs](../server/src/WebDrop.Core/ChannelCrypto.cs)：后端计算邀请 epoch/收件人计划，在单事务校验并提交域 envelopes、默认访问权和 epoch；按频道、域、epoch 过滤对象并校验历史起点、日志读取、下载与写入权限。客户端只生成密钥并封装到该计划指定的账号。
+7. [channelSend.ts](../web/src/core-bridge/worker/channelSend.ts)：文本编辑目前是新内容上传成功后删除旧条目。
+8. [reduce.ts](../web/src/store/reduce.ts)：作者和资源位置来自后端快照，没有作者签名或签名状态验证。
+
+## 用参考文档的威胁模型审视当前实现
+
+### 正常服务和被动泄露
+
+加密模式下，数据库和 blob 不保存资源明文或未封装的空间 K。数据密钥随机生成，不能仅凭登录 token 或数据库中的 verifier 直接推出保险库密钥或内容密钥。
+机密性仍依赖密码强度、端点安全和实际密钥分发过程；不能将此结论扩展为对主动恶意服务端的完整防护。
+
+### 主动恶意服务端
+
+- 邀请时，发送端从服务端目录读取收件账号公钥。当前没有可信签名身份、公钥固定或授权链验证；服务端替换公钥可使新邀请的密钥包被攻击者解开。
+- 服务端可改写未签名的成员、权限、作者和结构数据。客户端即使正确校验资源 AEAD，也不能据此验证作者、授权链或当前业务归属。
+- 已移除成员仍持有此前领取的频道域密钥。成员移除后的 epoch 轮换未实现；若恶意服务端继续向其提供后续密文，当前协议不能保证其无法解密。
+- 客户端没有验证 Owner 签名授权链；恶意服务端可伪造访问快照、作者归属或返回过期签名状态。
+
+因此，当前实现仍没有达到参考文档对“不可信服务器”的完整目标。现在的后端执行频道/域授权，并由客户端只解开获授权的密钥包；这能收束正常服务下的访问边界，但后端仍是身份目录、授权与事件归属的信任方。后端访问控制与客户端独立验证签名授权，是不同的安全保证。
+
+## 正确的前后端责任划分
+
+后端继续定义、存储和提供业务实体及接口，包括账户资料、设备目录、空间、频道、分组、文件夹、成员和同步游标。
+
+客户端负责生成和保管私钥、建立设备信任、签署并验证授权、校验 Key Envelope/epoch/消息签名、加解密资源，然后把验证通过的数据交给渲染层。
+
+这些客户端职责不应被当作“重复的业务实现”删除。CryptoProtocol 的结构可以统一定义并生成类型，但密码学验证必须在客户端执行，不能由不可信服务器替客户端宣布验证成功。
+
+## 当前前端可继续收束的部分
+
+已经由后端定义并生成前端 DTO 的有：账户资料、空间/频道/分组/文件夹、资源位置、频道设置与限制、成员和同步接口。`ChannelInfo`、`Item`、`PreviewKind` 等 camelCase 类型是 UI 或解密后的投影，不是第二份后端实体；AES 帧解析、账号私钥、Key Envelope 和对象 key 也必须留在客户端。
+
+仍有几处边界值得收回或明确：
+
+1. `SavedResource` 仍把 endpoint secret、链接等本机凭据与频道名称、成员人数上限等服务端展示快照放在同一结构；账号保险库也同步部分快照。建议拆为本机凭据、服务端快照和传输队列，离线快照只用于只读展示。
+2. Worker 从本地 `maxDownloads` 提供上传表单初始值；服务端已校验每个 GATED 文件的下载上限，缓存仅影响表单显示，不决定授权。
+3. `account.ts` 仍包含用户名输入规范化和账号本地恢复编排。服务端负责账户验证、设备 session、个人资料和保险库并发版本；浏览器只生成/持有私钥，并执行解锁加密保险库所需的本地 KDF。
+
+文件名、MIME、大小等 E2EE 正文结构和 `file.published` 不能移到服务器定义，否则服务器需解析或生成加密正文。有一处重复是有意的：加密文件元数据保留上传时原始 thread/folder，供解密后完整性核对；后端 WorkspaceLocation 表示当前可移动的位置。两者应明确命名为“原始来源”和“当前目录位置”，不能混为一个字段。
+
+参考文档把 Server 定义为不可信，同时要求客户端验证身份、签名授权和事件。后端权威管理账户与空间业务状态并不冲突，但这不代表客户端能防止恶意后端篡改状态。若保留“不信任 Server”的安全目标，后端可负责存储与 API 真值，签名身份、Capability 和 epoch 变更仍须客户端验证；在这些协议实现前，产品只能承诺正常服务下的后端权限执行与内容 E2EE，不能声称抵抗主动恶意服务器。
+
+边界原则：除端到端密钥生成、封装、解密与签名验证外，所有可由请求参数决定的业务规则都必须由后端计算和校验。前端校验、禁用按钮和隐藏菜单只能改善交互，不能决定账户角色、频道成员范围、权限、默认值、资源归属或状态转换。
+
+## 参考文档还需补足的协议细节
+
+### 已确认的实施目标(尚未部署)
+
+- 账号根签名密钥签发设备证书；设备私钥独立生成。新设备通过密码或 Passkey 解锁保险库恢复根密钥，不要求旧设备批准。
+- 首次收到的账号根公钥采用 TOFU 并展示“未核验”；之后密钥变化必须阻止静默更新。可选使用独立渠道/二维码核对指纹。TOFU 不防服务端在首次接触时替换密钥。
+- 第一阶段覆盖频道结构命令与聊天 create/edit/delete 事件。服务端拒绝无效签名并执行权限规则；浏览器同样验证签名、证书和授权链后才更新投影。
+- 现有服务端仍保存/排序/推送密文与事件；明文加解密继续只在浏览器。服务端分配的 seq 不由客户端签名，事件需绑定客户端 event ID、作者设备、类型、频道/epoch 和密文摘要。
+
+- **可信根**：首次确认用户/Owner 签名公钥的方式，避免服务端替换整个身份及授权链。
+- **设备恢复**：项目当前选择不要求旧设备审批；需明确密码、支持 PRF 的 Passkey 和不支持 PRF 的 Passkey 各自能恢复哪些账号/频道密钥，以及账号失陷的影响范围。
+- **签名格式**：确定签名覆盖的 subject/device/scope/permissions/version/epoch/密钥指纹等字段、规范编码和验证规则。
+- **状态一致性**：签名不能单独防止服务端返回旧的合法授权。需要定义版本、前序状态、可信检查点，以及跨设备回滚/分叉的检测范围。
+- **轮换过程**：原子提交新 epoch 与剩余设备的 envelopes，拒绝撤销后的旧 epoch 写入，处理离线设备、并发轮换和上传中的文件。
+- **历史读取策略**：新成员能否读历史、移除成员后哪些旧 FileKey 需要重新封装。重新封装不能撤回已被保存的旧密钥或明文。
+- **元数据可见性**：明确账号资料、频道/目录名称、资源归属和访问时间哪些允许服务端看到。文档中的“用户数据”不能替代字段级隐私范围。
+
+Epoch 轮换可以隔离正确切换后新数据的读取权限，不自动提供完整前向保密。服务端拒绝服务及删除密文仍属于无法单靠加密消除的可用性风险。
+
+## 按依赖推进的顺序
+
+1. 确定签名身份、可信根、设备证书与设备解包密钥；定义新协议版本，不迁移旧数据。
+2. 设计 Owner/Admin/Member 的签名 Capability，将管理能力和数据读取权拆开，并让后端给出可验证、原子提交的授权变更计划。
+3. 将账号级 envelopes 升级为设备级 envelopes，明确项目选择无旧设备审批后，Passkey 恢复、设备失陷与私钥复制的边界。
+4. 为成员/设备撤销实现每个 ChannelChat/ChannelFileGroup 的原子 epoch 轮换，覆盖离线成员、并发邀请和上传中的资源。
+5. 引入签名 ChatEvent、作者验证、可信同步检查点，再接入客户端投影和界面。
+6. 拆分 `SavedResource` 中的后端快照与本机密钥/队列，移除 Worker 对缓存权限字段的业务判断，在线操作以服务端授权为准。
+7. 根据多实例和存储规模需求替换数据库、事件通知和对象存储适配器。
+
+已完成的后端 CRUD、契约生成、Worker 分层、频道数据域、对象 key 封装、分帧 AEAD、完整性检查及持久化重试可以作为基础；下一阶段重点应转向可验证授权、设备级密钥分发、撤销轮换和前端缓存收束。

docs/frontend.md

@@ -4,6 +4,14 @@
 
 ## 1. 技术栈
 
+### 数据来源与契约
+
+HTTP 请求和响应类型由后端 DTO 生成到 `core-bridge/generated/api.ts`，不手写第二份接口模型。
+运行 `dotnet run --project tools/ContractGenerator -- <仓库目录>` 更新；`scripts/check-api-contract.mjs` 检查生成物是否与后端来源一致。
+`/info` 下发创建默认值、可选设置和部署限制，创建与设置页面通过 store 读取，不在组件里定义业务默认值。
+在线空间与分享列表从服务端刷新元数据；IndexedDB 作为离线缓存、凭据与发送队列。网络故障可显示缓存，认证或契约错误不能当作离线成功。
+账户资料、频道、分组、目录和资源归属通过后端接口加载及修改。加密资源元数据使用独立协议模型，不序列化 UI 的进度、预览、选中或历史版本状态。Worker 解密资源，store 保存服务端结构和资源投影，组件渲染。
+
 | 项 | 选择 | 说明 |
 |---|---|---|
 | 构建 | Vite | 纯客户端 SPA,不做 SSR |
@@ -93,8 +101,8 @@ type ItemState =
 | 降级防御 | 链接含 `k` 就只接受 enc 且认证通过的帧 |
 | 不把密钥、令牌、明文写入 `console`、错误上报、URL、`localStorage` | 「我的频道」只存 IndexedDB |
 | 便捷分享草稿预览 | 原始文件只缓存在创建者本机 IndexedDB,不会随文件帧上传;移除条目或封存时清理,用于刷新后继续预览草稿 |
-| 账号资源保险库 | Worker 派生登录凭据与 AES-GCM 密钥；仅同步 link/ownerLink、草稿清单、邀请私钥和移除墓碑；不含终端 S、设备名、缓存或文件 Blob。按账号/访客分库，会话在 Worker 中使用，通过本机 IndexedDB 恢复 |
-| thread 与虚拟文件夹 | `@webdrop/core` 用共享结构编码 `thread_id`/`folder_id` 和 CONTROL；mode 只切换是否加密；worker 解析控制正文，store 保留最新位置以防旧条目更新回退 |
+| 账号资源保险库 | Worker 派生登录凭据与 AES-GCM 密钥；同步资源访问凭据、邀请私钥和移除墓碑；不含个人资料、草稿内容、访客终端 S 或 Blob。按账号/访客分库，会话通过本机 IndexedDB 恢复 |
+| 频道与文件夹 | 后端持久化结构和资源归属，Worker 读取结构快照；加密文件元数据中的原始位置用于内容校验，UI 使用后端当前归属 |
 | 条目预览在沙箱 iframe 渲染;raw 内容只当纯文本显示或下载 | 无内联渲染,不使用 `dangerouslySetInnerHTML` |
 | 严格 CSP,所有脚本样式带 SRI,不使用内联脚本 | 与 architecture §5 一致 |
 | 不引入任何第三方脚本、统计、字体 CDN | 字体自托管 |
@@ -159,15 +167,15 @@ type ItemState =
 | 4 | 文件:流式上传下载、GATED 拉取、下载计数、预览、粘贴与拖放 |
 | 6 | PWA、Web Share Target、二维码与短配对码 |
 
-在 `@webdrop/core` 未就绪前,`core-bridge/` 按 protocol.md 定义的接口先放适配层和假实现,真实实现就绪后替换,组件与 store 不改。
+`@webdrop/core` 与真实 Worker 已接入，原型假数据与模拟连接实现已移除。接口测试使用测试替身，不保留第二套业务实现。
 
 ## 12. 实际边界与会话
 
-core-bridge/instance.ts 使用真实 Worker 实现，mock 仅用于原型和测试。账号与设备由 worker/account.ts 编排；账号密钥包通过 accountChannels.ts 与 channelGrant.ts 领取和核对；频道成员/设置/设备席位通过 channelResources.ts 调用 API；thread/folder/file.published 共用 channelThreads.ts 的加密 CONTROL 日志。
+core-bridge/instance.ts 使用真实 Worker 实现。账号、设备和个人资料由 worker/account.ts 与 accountProfile.ts 编排；账号密钥包通过 accountChannels.ts 与 channelGrant.ts 领取和核对；空间成员/设置/加入通过 channelResources.ts 调用 API；频道、分组和目录由 channelThreads.ts 调用后端。workspaceRecords.ts 只读取加密文件元数据，不处理账户或结构操作。
 
 @webdrop/core 仅实现纯密码学与帧协议，不访问数据库或网络。sessions.ts 管本机已解锁会话。transfer.ts 管持久化密文发送队列，队列按资源/创建顺序索引，确保文件密文帧先于目录记录上传。downloadStorage.ts 优先使用 OPFS 逐块写入临时文件，认证结束后交付；不支持时最多 64 MiB 的 Blob 回退。
 
-频道和 Share 各有独立领域 API 与生命周期；Share 封存由服务端事务清除 owner_hash，不能再写。账号保险库同步个人资料、邀请私钥、资源凭据和移除墓碑；设备 S、文件缓存与 outbox 保留本机。
+空间和 Share 各有独立领域 API 与生命周期；Share 封存由服务端事务清除 owner_hash，不能再写。账号保险库同步邀请私钥、资源凭据和移除墓碑；个人资料从后端读取，设备 S、文件缓存与 outbox 保留本机。
 
 ## 13. 账号会话恢复与频道密钥领取
 
@@ -177,7 +185,7 @@ core-bridge/instance.ts 使用真实 Worker 实现，mock 仅用于原型和测
 
 ## 14. 用户概念映射与分组
 
-界面 Space 对应既有顶层 ChannelInfo 与 /c/:id；界面频道对应 ThreadInfo 和 thread_id。ChannelGroupInfo 属于当前空间，ThreadInfo.groupId 可选。store 从 group-created/group-renamed/thread-grouped 事件重建分组；threadGroups 保留最新归属，避免延迟的创建事件将频道移回旧分组。分组不是文件夹，也不是成员/密钥边界。
+界面 Space 对应既有顶层 ChannelInfo 与 /c/:id；界面频道对应后端 WorkspaceChannel 和帧协议 threadId。store 直接渲染服务端结构快照，不重放创建/重命名/分组事件。ThreadInfo 与 FolderInfo 只将后端可空字段转成 UI 的可选字段。分组不是成员或密钥边界。
 
 ## 15. 文件交互边界
 
@@ -187,9 +195,9 @@ ContextMenu 是无业务 UI，负责 portal、视口限制、键盘焦点和关
 
 ## 16. 文件聊天消息与身份快照
 
-ItemBase.author 为可选发送者快照 {username,displayName,avatar?}。文件的快照放入已有 file.published 加密目录记录，文本通过 item.author CONTROL 记录关联。store 的 authors 索引支持身份记录先于条目到达，并在晚到的下载/进度更新中保留身份，避免取文件内容后丢失头像。该快照用于展示，不代表逐账号数字签名。
+ItemBase.author 由服务端资源作者和账号资料投影得到，晚到的解密内容不能覆盖服务器提供的作者与位置。客户端提供的作者声明不能覆盖服务端资料。这是服务端身份归属，不是端对端逐账号签名。
 
-ChatPane 订阅当前频道的条目 ID，ChatMessage 单独订阅条目状态和上传进度；文件目录变成文件消息，不重复创建独立文本通知。预览/下载继续经已有 store action，移动文件不会重新上传。GATED 内容只有明确操作后才读取。
+ChatPane 订阅当前频道的条目 ID（乐观发送：store 的 sendText/sendFiles 先写入 `local:` 占位项，worker 经 `localId` 带回后由 reduce 替换，失败可 `retrySend`），ChatMessage 单独订阅条目状态和上传进度；文件目录变成文件消息，不重复创建独立文本通知。预览/下载继续经已有 store action，移动文件不会重新上传。GATED 内容只有明确操作后才读取。
 
 ## 17. 本机凭据保存
 

docs/protocol.md

@@ -1,5 +1,15 @@
 # 协议 v1
 
+### 频道数据域边界
+
+新工作区的空间凭据只用于空间访问与管理，不作为频道内容密钥。每个频道有独立 chat/files 数据域与 epoch；客户端为每个条目生成随机 32 字节对象密钥，以对应数据域的 epoch key 用 AES-256-GCM 封装。封装上下文绑定空间、频道、数据域、epoch 和条目 ID。服务端保存对象归属与密钥封装，不能获得对象明文密钥。客户端解密必须先取得对应数据域授权，禁止回退到空间密钥。
+
+域密钥由创建者随机生成，再通过现有账号 ECDH 公钥信封逐账号封装；域信封上下文包括空间 ID、频道 ID、域名和 epoch。邀请前服务端按成员权限和历史设置生成 epoch/收件人计划；浏览器只为计划中的收件人封装密钥，服务端在单事务中重算并校验邀请、权限、envelopes 和 epoch。服务端根据登录身份只返回该账号可读域的信封和匹配对象索引，并在日志读取、文件下载及写入时执行成员权限检查。默认频道的新成员获得 chat read/write、files read/upload；新增频道的访问不会由空间成员身份自动推导。Owner 可分别决定新成员能否读取聊天和文件历史。关闭某域历史时，邀请流程生成新 epoch，并将新密钥给现有授权成员与新成员；新成员不获旧 epoch 信封。未启用 E2EE 时，后端用服务端维护的 crypto revision 作为访问起点，过滤历史日志和目录位置。该策略不撤回已经交付的密钥；已移除成员的撤销轮换目前尚未实现。
+
+该模型的服务端是授权执行方，而不是可被客户端验证的授权来源：目前没有 Owner 签名 Capability、账号签名身份、设备证书或事件签名。首次邀请公钥也来自服务端目录，公钥替换风险仍存在。不能把 AEAD 校验或服务端权限过滤描述成对恶意服务端的端到端授权验证。
+
+新版本的频道、分组、目录和文件归属通过后端空间结构接口管理。资源内容继续采用浏览器端加密。`file.published` 的 item 使用独立协议结构，不序列化 UI 的 state、preview、remaining 或版本列表。接收端只重建资源渲染状态，不从资源正文构建账户或空间结构。
+
 本文是协议的权威来源。所有实现(服务端、`@webdrop/core`、将来的 CLI)必须通过 `test-vectors/` 中的向量。
 
 ## 1. 编码约定
@@ -12,10 +22,10 @@
 |---|---|---|
 | `channel_id` | 16 B | 随机,客户端生成 |
 | `item_id` | 16 B | 随机,客户端生成 |
-| `K` | 32 B | 频道密钥,仅 enc 模式,按账号加密封装；可选能力链接使用 fragment |
+| `K` | 32 B | 空间/临时频道访问凭据；新工作区内容加密不使用它，可选能力链接使用 fragment |
 | `A` | 32 B | 管理密钥,独立随机,只存在于所有者链接 |
 | `W` | 32 B | 写密钥,仅 raw 模式且成员可上传时 |
-| `S` | 32 B | 终端密钥,每个频道每个终端各生成一个,仅存本地 |
+| `S` | 32 B | 便捷分享的终端密钥(创建者与读者),仅存本地;频道与空间不使用,只凭账号会话鉴权 |
 
 ## 2. 模式与链接
 
@@ -70,7 +80,7 @@ raw 模式下 `T_owner` 同样由 `A` 派生;`T_write = W`。
 | 1 | SNAPSHOT | 该条目是频道的「最新快照」,取代之前的快照条目 |
 | 2 | GATED | 不通过实时推送内联分发,只能按条目拉取,并计下载次数 |
 | 3 | ENC | 负载为 AES-GCM 密文,必须与频道模式一致 |
-| 4 | CONTROL | 频道结构控制条目 |
+| 4 | CONTROL | 加密资源元数据记录 |
 | 5-7 | 保留 | 必须为 0 |
 
 服务端拒绝不符合上述规则的封装,但从不解析负载。
@@ -120,13 +130,13 @@ meta_len (u16) ‖ meta_json (UTF-8) ‖ content_bytes ...
 | `mime` | 可选 |
 | `size` | 可选,内容总字节数(流式时可省略) |
 | `ts` | 毫秒时间戳,仅供参考,排序以 seq 为准 |
-| `dev` | 可选,设备名 |
+| `dev` | 已弃用(v7 起客户端不再写入,读取时忽略);发送者以服务端记录的账号为准 |
 | `thread_id` | 可选,频道 thread ID |
 | `folder_id` | 可选,文件的虚拟文件夹 ID |
 
 第 1 帧起,`data` 全部是内容字节。小内容(文本、JSON)一帧完成,没有额外开销。
 
-**频道 thread 与文件夹**:客户端把 thread/folder 元数据放在上述共享元数据中（enc 时加密，raw 时服务端可见）。thread 的创建、重命名,文件夹的创建/重命名,以及条目移动等操作以 `kind=other` 的 CONTROL 条目追加到同一频道日志;控制正文是版本化 JSON,仅客户端识别。它们不增加服务端表或第二套同步协议。新内容必须归属已创建的 thread；前端新建频道后自动发布“常规”thread 创建记录。GATED 的 announce 不含元数据，但 file.published 加密目录记录可在不下载内容时提供名称和归属；没有目录记录时显示通用占位符。
+**频道 thread 与文件夹**:客户端把 thread/folder 元数据放在上述共享元数据中（enc 时加密，raw 时服务端可见）。频道、分组、文件夹和条目归属由后端结构接口管理，不写入内容日志。新建空间与初始“常规”频道由后端原子创建。GATED 的 announce 不含元数据，file.published 加密记录提供名称和原始归属；目录记录未到达时显示等待同步占位符。
 
 **raw 模式（API 契约 2）**:负载使用与 enc 相同的 `u16 meta_len ‖ meta_json ‖ content` 条目结构，只是不加密。名称、thread/folder ID 与其他元数据对服务端可见。旧版“纯字节、无元数据”的 raw 负载不属于新应用契约，旧客户端会被 API 主版本检查拒绝。
 
@@ -134,7 +144,7 @@ meta_len (u16) ‖ meta_json (UTF-8) ‖ content_bytes ...
 
 ## 8. 日志、序号与条目生命周期
 
-`CONTROL=0x10` 标记频道结构控制条目；保留位为 `0xE0`。控制条目必须是非 GATED、非 SNAPSHOT 的 FINAL 单帧，payload 最多 16,400 B；其生命周期为频道生命周期，不受普通内容 TTL 或 max_items 淘汰。每频道最多 4096 条控制记录，仍计入总字节配额。加密和非加密频道使用相同控制正文与日志处理。
+`CONTROL=0x10` 标记加密资源元数据记录；保留位为 `0xE0`。控制条目必须是非 GATED、非 SNAPSHOT 的 FINAL 单帧，payload 最多 16,400 B；其生命周期为频道生命周期，不受普通内容 TTL 或 max_items 淘汰。每频道最多 4096 条控制记录，仍计入总字节配额。加密和非加密频道使用相同控制正文与日志处理。
 
 频道维护一条服务端排序的**日志**,每条记录的序号 `seq` 是 u64,频道内单调递增。
 
@@ -151,7 +161,7 @@ meta_len (u16) ‖ meta_json (UTF-8) ‖ content_bytes ...
 **推送规则**:
 - 非 GATED 条目以 frame 记录推送给订阅者。服务端强制:**非 GATED 条目必须是单帧且带 FINAL**(`frame_index = 0`)。
 - GATED 条目只推送一条 announce,字节通过条目拉取接口取得(见 api.md),`from=0` 的拉取计入下载次数。
-- `from>0` 只有在同一终端此前已对同一条目成功发起 `from=0` 后才是有效续传;服务端按资源、条目和终端绑定这份续传许可,任意跳到中间帧不能绕过下载次数。
+- `from>0` 只有在同一下载方(频道按用户)此前已对同一条目成功发起 `from=0` 后才是有效续传;服务端按资源、条目和下载方绑定这份续传许可,任意跳到中间帧不能绕过下载次数。
 - 因此客户端上传**多帧条目(文件)或带下载上限的条目时,必须设置 GATED**。
 - 同一条目的所有帧,SNAPSHOT 与 GATED 标志必须一致;FINAL 不能早于已存在的更大序号;已有 FINAL 之后不能再追加更大序号的帧。GATED 条目的帧允许乱序到达(并行上传),条目拉取只返回从起点开始连续的帧。
 
@@ -165,14 +175,14 @@ meta_len (u16) ‖ meta_json (UTF-8) ‖ content_bytes ...
 
 带 SNAPSHOT 的条目取代频道中之前的快照条目(最后写入者胜)。快照必须是**非 GATED 的单帧**(整份状态不超过一帧,约 1 MiB),所以新快照一被接受,服务端就在同一个事务里删除旧快照并产生一条 `reason = 4` 的 tombstone。一个频道在 v1 里只有一个快照槽,多文档请使用多个频道。
 
-## 10. 终端与席位
+## 10. 用户、设备与成员人数
 
-- 终端在本地为每个频道生成随机 `S`,请求中带 `S`;服务端保存 `SHA-256(S)` 作为终端标识。
-- 终端通过显式的加入请求(`POST .../seats`)占用一个席位;创建者的终端在创建时自动入席。席位已满则拒绝新终端(`seats_full`),已入席的终端可重复加入(幂等)和重连。未入席的终端访问频道返回 `not_joined`。
-- 不同频道使用不同的 `S`,避免服务端把同一设备关联起来。
-- 终端可以加密一个设备名上传,所有者能看到成员列表和设备名,并可以释放席位。
-- 终端可更新自己的名称;所有者也可重命名任意席位。enc 模式重命名仍使用同一份加密设备标签,并将 AAD 绑定目标 endpoint hash;raw 模式标签仍为明文。所有者移除席位后,该终端不能继续读取频道,但持有成员链接的人仍可重新加入(若有空席位)。
-- **设备名格式(enc)**:`iv(12 B 随机) ‖ AES-256-GCM(K_label, utf8 名称) ‖ tag(16 B)`,AAD = `"WD1L"`(4 B ASCII)‖ `channel_id` ‖ `endpoint_hash`(32 B,即 `SHA-256(S)`)。总长不超过 256 B,所以名称最多 228 字节 UTF-8。使用派生子密钥 `K_label` 而不是直接用 `K_enc`,避免同一密钥同时用于 HKDF 和 AES-GCM;AAD 绑定终端,服务端无法把一个终端的设备名挪到另一个席位上。raw 模式下设备名是明文 UTF-8。
+- **成员是用户(账号)**。设备只是账号的属性：同一账号可在任意多台设备登录，只占一个成员名额；账号成员的请求凭有效的账号 session 鉴权，不再需要终端密钥，也不登记终端。
+- **频道强制登录**（v8）：没有账号会话的请求一律返回 `account_required`，不再有未登录访客（没有 `allow_guests`、`/guests`、访客终端席位）。持链接的人先登录，再通过显式的加入请求（`POST .../join`）成为成员；未加入的账号访问频道内容返回 `not_joined`；所有者通过撤销邀请移除成员。便捷分享不受影响。
+- 频道设置字段 `max_members`（v7 前叫 `seats`）是**最大成员人数**。owner 和每个唯一账号各计一人，同一账号的额外设备不增加人数。成员人数达到上限时，新的成员加入返回 `members_full`。
+- 受限下载（GATED）的计数单位是「下载方」：按用户；同一下载方对同一条目重复发起 `from=0` 才算续传。
+- 在线状态由服务端按账号统计（`members` 接口的 `online`、`devices`、`online_devices`），只来自内存里的订阅登记，不写库。
+- **已移除**：每终端的加密设备名（`K_label`、AAD `WD1L`、`PUT .../seats/me` 与 `.../seats/{hash}/label`）和设备席位清单。设备名只在账号设备管理里存在（`/accounts/devices`）。`K_label` 的派生仍保留在 §3，为已发布的测试向量保持稳定，但不再被使用。
 
 ## 11. 创建与验证码
 
@@ -193,7 +203,7 @@ meta_len (u16) ‖ meta_json (UTF-8) ‖ content_bytes ...
 | 设置 | 默认 | 范围 |
 |---|---|---|
 | `name` | 无 | 可选,最多 48 个字符;所有频道成员和服务端可见 |
-| `seats` | 2 | 1..64(服务端可配置上限) |
+| `max_members`(v7 前叫 `seats`,最大成员人数) | 2 | 1..64(服务端可配置上限);每个账号计一人,其多设备不增加人数 |
 | `members_can_upload` | true | |
 | `delete_policy` | `own` | `owner_only` / `own` / `anyone` |
 | `ttl_seconds` | 86400 | 最长 604800,每个条目从创建起算 |
@@ -212,6 +222,8 @@ meta_len (u16) ‖ meta_json (UTF-8) ‖ content_bytes ...
 | 每频道字节数 | 1 GiB |
 | 每频道条目数 | `max_items` |
 
+工作区对象帧使用独立容量限制：单个工作区默认最多 1 TiB，单个 `WorkspaceChannel` 的 Files 域默认最多 10 GiB；Files 域用量以非 CONTROL 帧字节计，删除条目后释放用量。其他未绑定工作区对象的旧式频道仍遵循上表 1 GiB 限制。实际配置值由 `/info` 返回，客户端不得自行推导或执行配额。
+
 ## 14. 接收方校验算法
 
 对 enc 频道的每个条目:
@@ -232,7 +244,7 @@ meta_len (u16) ‖ meta_json (UTF-8) ‖ content_bytes ...
 | 模式 | enc 或 raw | **只有 enc** |
 | 谁能写 | 所有者和成员 | 只有创建者,且只在草稿阶段 |
 | 寿命 | 长期(TTL 滚动续期) | 短,封存后到期即清 |
-| 访客 | 成员,占席位 | 只读访客,按终端计数,不展示人数 |
+| 谁能读 | 已登录的成员(账号) | 持链接的任何人,无需账号;访客按终端计数,不展示人数 |
 
 分享与频道**共用同一个 16 字节 id 空间**,服务端保证全局唯一,所以同一个 id 不可能既是频道又是分享。分享 id 在频道接口上返回 `not_found`,反之亦然。
 
@@ -330,27 +342,45 @@ meta_len (u16) ‖ meta_json (UTF-8) ‖ content_bytes ...
 - `test-vectors/` 提供固定输入、固定输出:密钥派生、令牌、加解密、padding、封装编解码,以及篡改、重排、截断、换频道的负例,必须全部通过。
 - 本版**预留**但不实现:口令叠加(Argon2id)、短配对码(PAKE)、多快照槽。
 
-## 17. 按账号分发频道密钥
+## 17. 账号凭据与频道域密钥
 
-频道内容仍使用共享 K 加密。创建者用自己的账号 P-256 公钥封装 owner 凭据，随创建请求的 key_package 与频道、owner 成员记录在同一事务内保存。邀请时用收件账号公钥封装 member 凭据，服务端原子保存邀请和密钥包；账号接受邀请并成为成员后，可只凭账号 session 从 /accounts/channels 取回自己的密钥包，不需要含密钥的 URL，也不要求邀请者在线。成员包不得包含管理密钥 A。
+空间访问凭据用于服务端资源/终端鉴权，不是频道内容根。创建者用自己的账号 P-256 公钥封装 Owner 凭据，随空间、默认频道、Owner 成员记录原子保存。账号接受空间邀请后，可凭账号 session 从 `/accounts/channels` 取回自己的空间凭据；账号成员不登记终端，实际打开空间时只确认成员关系（`POST .../join` 幂等）。
 
-密钥包沿用邀请的 ECDH、HKDF、AES-GCM，AAD 绑定收件账号与频道 ID。服务端只保存 opaque 密文；成员私钥保存在口令加密的账号保险库。成员登录后解开保险库、取回密钥包，在 Worker 内恢复频道会话；新设备生成独立 S，打开频道时才占设备席位。待接受的邀请不会自动占席位。
+内容加密密钥由浏览器生成。每个频道各有独立 `chat` 与 `files` 域，每域从 epoch 1 开始使用随机 32 B key。域信封沿用账号 ECDH、HKDF、AES-GCM，AAD 绑定账号、空间 ID、频道 ID、域名与 epoch。服务端保存 opaque 密文，只向通过频道/域读取授权的账号返回信封。每条消息、文件和加密发布元数据使用独立随机 32 B 对象密钥；对象密钥由域 key 的 AES-GCM 封装，AAD 绑定空间、频道、域、epoch 和 item ID。
 
-撤销成员时同时删除密钥包和席位。此举不能收回已交付的 K 或历史明文；当前没有轮换密钥或前向保密。仅知道频道 ID 或登录账号并不足以获得密钥；新账号必须得到现有持钥 owner 的授权封装。邀请公钥仍来自服务端目录，尚无外部指纹核验。
+默认频道成员权限是 chat read/write 与 files read/upload；其它频道不能从空间成员身份推导访问权。Owner 邀请时可分别允许新成员读取已有聊天和文件。关闭历史会对对应域创建新 epoch，把新 key 封装给现有授权账号和新成员，不向新成员分发旧 epoch。此策略不撤回此前已交付的密钥，也不等于成员移除时的完整密码学撤销；已加入成员撤销后的轮换、离线和并发协议仍待实现。
+
+服务端会按账号权限过滤频道结构、域信封、对象索引和日志/下载，并拒绝无写入授权或旧 epoch 的新帧。这是服务端执行的访问策略，不是客户端可独立验证的签名 Capability。域密钥封装目前按账号而非设备，目录公钥替换风险、恶意服务端伪造结构/作者和事件签名缺失仍然存在。
 
 
 ## 18. 频道加密文件目录
 
-文件密文帧之后，在同一发送队列追加 CONTROL file.published，正文包含 item.id、kind=file、threadId、folderId（可选）、name、mime、size、ts、deviceId、gated。记录与 thread/folder 控制记录共用 webdrop.workspace v1 正文。名称/类型/大小/原始 thread/folder 必须与文件第 0 帧元数据相符。目录允许先显示名称，但不得因此自动下载 GATED 内容。
+文件密文帧之后，在同一发送队列追加 CONTROL file.published，正文包含 item.id、kind=file、threadId、folderId（可选）、name、mime、size、ts、deviceId、gated。资源记录使用 webdrop.workspace v1 正文。名称/类型/大小/原始 thread/folder 必须与文件第 0 帧元数据相符。目录允许先显示名称，但不得因此自动下载 GATED 内容。
 
-客户端只有在当前日志存在对应文件帧或 announce 时展示目录；文件墓碑清除目录可见状态，全量重放时不恢复不存在/过期文件。目录记录属于 CONTROL，仍受 4096 条控制记录和频道字节配额限制。文件移动覆盖位置索引，不重新加密原始文件，不改变最初认证的内容元数据。
+客户端只有在当前日志存在对应文件帧或 announce 时展示目录；文件墓碑清除目录可见状态，全量重放时不恢复不存在/过期文件。目录记录属于 CONTROL，仍受 4096 条控制记录和频道字节配额限制。文件移动由服务端更新归属，不重新加密原始文件，不改变最初认证的内容元数据。
 
 ## 19. 空间内的频道分组
 
-界面顶层“空间”对应协议 channel，界面“频道”对应 thread。沿用 webdrop.workspace v1 CONTROL 正文：group.create {id,name}，group.rename {id,name}，thread.group {id,groupId}（null 表示未分组）；thread.create 可包含 groupId。ID 为 UUID，name 为 1–80 个非控制字符。分组仅组织频道，成员、内容密钥和日志仍归属于空间。旧创建记录不含 groupId，作为未分组频道重放。
+界面顶层“空间”对应 API space/底层同步资源，界面“频道”是空间中的 WorkspaceChannel，帧元数据 threadId 映射到频道 ID。频道和分组由后端结构接口创建、重命名和管理归属，名称限制与关联验证由后端实施。成员与同步日志归属于空间，频道各自拥有 chat/files 密钥域；分组仅组织频道，不建立新授权或密钥。客户端不重放 group.create、thread.create 等结构记录。
 
 ## 20. 发送者展示快照
 
-file.published.item 可携带 author {username,displayName,avatar?}；另有 item.author {itemId,author} CONTROL，为文本关联展示身份。username 使用当前账号固定用户名，displayName 最多 48 个字符，avatar 仅允许不超过 8000 字符的 PNG/JPEG/WebP data URL。头像在客户端压缩为最多 64×64 后写入加密正文，不改变内容帧、密钥派生或鉴权头。
+聊天发送者由服务端已存条目的 authorAccount 与后端个人资料决定。file.published 不写入作者声明。头像在 Worker 内缩放为最多 64×64 后用于渲染，不影响加密帧或鉴权。
 
-快照是持钥成员提供的展示资料，不是发送者签名。无 author 的旧记录回退设备名；客户端不得将此类内容标记为当前账号发送。结构记录随既有 CONTROL 生命周期处理，实际消息可见性仍由条目和墓碑决定。
+服务端提供的作者归属与个人资料不代表端对端发送者签名；资源密文仍由浏览器验证。未关联账号的访客资源回退设备来源，不推测当前用户。
+
+## 21. 签名扩展基础
+
+本节定义后续签名授权和签名事件共用的签名原语；在对应 API 与事件模型完成前，它**不改变现有无签名请求的行为，也不表示频道操作已启用验签**。
+
+- 算法为 ECDSA P-256 / SHA-256。签名线格式为 64 字节 IEEE P1363 `r ‖ s`；公钥按 P-256 JWK 的 `x`、`y` 表示，各为 32 字节 base64url。
+- 被签名字节为 `"WDS\x01" ‖ kind_len(u16) ‖ kind(ASCII) ‖ payload_len(u32) ‖ payload`，整数大端。`kind` 为 1–64 字节、匹配 `[a-z][a-z0-9._-]*`；payload 最大 1 MiB。
+- `kind` 必须区分对象用途，不能跨类型复用签名。payload 后续按设备证书、Capability、ChatEvent 各自定义唯一字段顺序和二进制编码；禁止直接签未经规范化的 JSON。
+- 浏览器和服务端都必须先校验 payload 结构、身份绑定、授权范围和上下文，再验签；任一步失败均拒绝操作。服务端接受请求不代替浏览器验签。
+- 此原语只证明某密钥持有者签署了这些字节，不证明公钥属于声称的账号，也不防止服务端隐藏、回滚或向不同客户端展示分叉状态。
+
+`device.certificate` 的 payload 为 `username_len(u8) ‖ lowercase_username(ASCII) ‖ device_id_len(u8) ‖ lowercase_device_id(ASCII UUID D 格式) ‖ device_public_x(32 B) ‖ device_public_y(32 B)`。账号根密钥签发此证书；设备密钥预留用于签署频道结构命令和聊天/文件事件。新设备通过密码/Passkey 解锁保险库恢复账号根密钥，不要求旧设备在线批准。其他账号第一次看到某账号根公钥时采用 TOFU：首次固定并展示“未核验”状态，后续变化不得静默接受；这不能防止首次接触时服务端替换密钥。成员可通过独立渠道比较指纹。透明日志、跨客户端一致性证明和历史检查点属于后续阶段。
+
+`content.event` 的 payload 顺序为 `space_id(16 B) ‖ channel_id_len(u8) ‖ channel_id(ASCII UUID) ‖ username_len(u8) ‖ username(lowercase ASCII) ‖ device_id_len(u8) ‖ device_id(lowercase ASCII UUID) ‖ event_id(16 B) ‖ event_kind_len(u8) ‖ event_kind(ASCII) ‖ domain(u8:chat=1,files=2) ‖ epoch(u32) ‖ item_id(16 B) ‖ frame_count(u32) ‖ manifest_hash(32 B) ‖ target_present(u8) ‖ target_item_id(16 B 或全零)`。`manifest_hash = SHA-256("WD1M" ‖ frame_count(u32) ‖ (frame_index(u32) ‖ SHA-256(完整 frame envelope))...)`，帧必须从 0 连续排列。事件类型包括 `chat.create/edit/snapshot/delete`、`file.publish/catalog/delete`。FINAL 上传头带事件字段；后端确认证书、签名、对象作者/domain/epoch/权限及数据库帧清单一致后，在对象元数据保存签名。`CryptoState` 按域授权过滤后把签名材料返回客户端。浏览器在投影完整帧前验设备证书、TOFU 根 key、事件签名和本地 manifest。
+
+当前已接通新账号根公钥、设备证书校验，以及有账号设备签名密钥的对象最终帧验签/作者 manifest 校验；已登记签名设备的删除也要求签名并把删除证明保存到对象元数据；未注册签名设备的旧账号仍走兼容路径。**频道结构命令和成员/权限变更尚未签名**。TOFU 首次接触风险、服务器分叉/回滚、撤销设备密钥轮换仍未解决，不能宣称已完整抵抗主动恶意服务端。

docs/threat-model.md

@@ -16,7 +16,7 @@
 
 | 能看到 | 说明 |
 |---|---|
-| 频道 id、模式、设置 | 包括共享频道名、席位数、权限、TTL、下载上限等,服务端需要据此执行 |
+| 频道 id、模式、设置 | 包括共享频道名、成员人数上限、权限、TTL、下载上限等,服务端需要据此执行 |
 | 帧数量、时间、序号 | 追加顺序由服务端分配 |
 | 密文大小 | 经过档位 padding,见 protocol §6 |
 | 帧标志 | FINAL、SNAPSHOT、GATED、ENC |
@@ -25,11 +25,12 @@
 | 下载次数 | 服务端计数 |
 | 传输层信息 | IP、TLS 指纹、访问时间 |
 | 账号服务可见 | 用户名、口令 verifier、保险库密文大小和更新时间；不会看到保险库明文、频道密钥或分享链接 |
+| 业务结构和个人资料 | 账号昵称头像、空间和频道名称、分组、文件夹名称、资源归属、资源作者；由后端管理，不属于资源内容的端对端加密承诺 |
 
 | 看不到(enc 模式) | 说明 |
 |---|---|
 | 内容 | 文本、JSON、文件字节 |
-| 文件名、类型、总大小、设备名 | 都在加密的条目元数据里 |
+| 文件名、类型、总大小、文件内设备标签 | 都在加密的条目元数据里 |
 | 密钥 K、管理密钥 A | 由客户端保管，以账号公钥封装的密文可存服务器；可选分享链接使用 fragment |
 
 `raw` 模式下服务端能看到全部负载,界面必须明确提示。
@@ -53,14 +54,14 @@
 | 模式降级(enc 换成 raw) | 链接带 `k` 就只接受 enc 且认证通过的帧,不匹配直接拒绝 |
 | 重放旧帧 | 同一条目内 (item_id, frame_index) 唯一,服务端幂等,客户端按条目去重 |
 | 服务端隐瞒或删除条目 | **无法防止**(可用性),见 §6 |
-| 链接泄露 | 链接即能力。席位上限限制加入数,所有者可释放席位和删除频道 |
+| 链接泄露 | 链接即能力。成员人数上限限制账号成员数,频道只接受登录账号,所有者可撤销成员和删除频道 |
 | fragment 外泄 | 取出后立即 `history.replaceState`;`Referrer-Policy: no-referrer`;不把 K 放进查询串 |
 | XSS | 严格 CSP;条目预览在沙箱中渲染;`raw` 内容不内联渲染,下载带 `attachment` 和 `nosniff` |
 | 暴力猜频道 id | id 128 位随机 |
 | 撞库/截获账号登录 | 客户端 PBKDF2 派生登录凭据，经 HTTPS 传输；服务端另存独立随机 salt 的 PBKDF2 慢哈希，并限流。TLS 或运行终端泄露仍可能暴露可登录凭据 |
 | 账号数据库泄露 | 数据库只有加盐慢哈希，不能直接用于登录；弱口令仍可被离线猜测。登录凭据不能直接派生保险库密钥 |
-| 账号混用/设备身份混用 | 按账号与访客隔离 IndexedDB，切换时中止后台任务；保险库不包含设备 S，每台设备单独生成 |
-| 绕过频道加入规则 | 服务端检查 owner/member 角色、邀请、密码、账号 session 与设备席位；加密选项不会绕开权限 |
+| 账号混用/设备身份混用 | 按账号隔离 IndexedDB，切换时中止后台任务；保险库不包含设备 S，每台设备单独生成 |
+| 绕过频道加入规则 | 服务端检查 owner/member 角色、邀请、密码、账号 session(没有则一律拒绝)、成员人数；加密选项不会绕开权限 |
 | 匿名滥用与 DoS | 创建时的 Cap 验证码(工作量证明由 Cap 提供)、限流、频道配额、条目数和字节数上限 |
 
 ## 5. 前端信任根(残余风险)
@@ -101,6 +102,6 @@
 
 ## 8. 账号设备与本机缓存
 
-同一账号的各设备拥有独立 sessions 和频道 S。撤销设备会删除该设备 sessions 与频道席位；不会移除账号成员或其他设备。撤销不能擦除已下载数据、已持有的频道 K 或被复制的账号私钥。当前未实现密钥轮换，不声称前向保密。
+同一账号的各设备拥有独立 sessions，但在频道成员上限中只计一个账号成员，成员请求凭账号 session 鉴权。撤销设备会删除该设备 sessions；不会移除账号成员或释放其成员名额，也不会影响其他设备。撤销不能擦除已下载数据、已持有的频道 K 或被复制的账号私钥。当前未实现密钥轮换，不声称前向保密。未登录访客无法跨设备去重，每个访客终端单独计入人数上限。
 
 本机记住登录允许本浏览器使用者访问账号，退出时删除自动恢复凭据。OPFS 存储解密后临时文件，正常退出账号时清理；浏览器崩溃可能留下本机缓存，它不属于服务端密文。

docs/ui-design.md

@@ -78,7 +78,9 @@ WebDrop 是**暂存区**,频道工作区:聊天按 thread 展示，文件按 thr
 
 ### 6.1 手机:频道导航与聊天/文件切换
 
-顶栏下显示账号频道导航与当前频道的 threads。新建频道自动创建“常规”thread，成员可直接聊天和上传。下方用“聊天 / 文件”切换同一 thread 的内容，聊天输入位于底部；文件区与桌面共用目录路径、上传、文件夹、排序、移动和预览组件。
+进入频道就是纯聊天界面：单行顶栏（≡、# 频道名、加密图标、搜索、⋯）加底部输入框，没有页签。空间切换、频道列表、本空间的「文件 / 成员 / 邀请 / 分享」、账号与外观都在左侧抽屉（≡ 打开，返回键关闭）；点「文件」「成员」整页打开，左上角 ‹ 回到聊天。⋯ 里是空间设置、分享、邀请。触屏没有悬停，消息上不常驻删除按钮，点一下消息弹出菜单（复制、删除）。新建频道自动创建“常规”thread。文件页与桌面共用目录路径、上传、文件夹、排序、移动和预览组件。
+
+频道加载中先画出页面框架（骨架屏：顶栏、频道列表、消息、输入框的灰色占位），不留白屏；等待不足约 300ms 时不显示，避免闪烁；占位轻微呼吸闪动，尊重「减少动效」。不用假进度条。加载失败时在骨架屏上给出错误与「重试」「回到首页」。
 
 ### 6.2 电脑:频道与 threads | 聊天 | 线程文件
 
@@ -99,43 +101,26 @@ WebDrop 是**暂存区**,频道工作区:聊天按 thread 展示，文件按 thr
 
 ### 6.4 首页(初始状态)与页面
 
-首页把「临时分享」与「设备频道」作为两个并列入口:前者用于发一段临时文本或文件,后者用于多设备长期同步。
+首页把「便捷分享」与「空间」做成两个并列分区（宽屏左右并列，窄屏上下排列，中间一条细线分隔），各有图标和一句话定位：
 
-主页右上角提供外观菜单,可跟随系统或切换亮色/暗色。右下角分别显示前端和后端的 tag 与短 commit hash,并显示换算为上海时间的构建时间(`yyyy-MM-dd HH:mm`);前端还显示包版本。无法取得 tag 时如实显示「未标记」。
+- **便捷分享**（左）：临时 · 只读 · 对方无需账号，端到端加密。输入区（文字、拖入/选择/粘贴文件）加「创建分享」，下面紧跟「我的分享」列表。是写完即发的操作区。
+- **空间**（右）：长期 · 多人 · 登录使用。先列「我的空间」（名称、加密、角色、人数上限），底部是「新建空间」「加入空间」。是进入长期工作区的入口。
 
-```
-┌──────────────────────────────────┐
-│            WebDrop               │
-│ 在自己的设备之间传文件和文本,也可分享给别人。│
-│ ┌ 临时分享 ───────────────────┐ │
-│ │ 输入或粘贴临时文本…          │ │
-│ │ 拖入文件 / 文件名列表         │ │
-│ │ [选择文件] [粘贴] [创建临时分享]│ │
-│ └────────────────────────────┘ │
-│ ┌ 账号与同步 ─────────────────┐ │
-│ │ 用户名 / 密码  [登录并同步]   │ │
-│ │ 资源清单先在本机加密后同步     │ │
-│ └────────────────────────────┘ │
-│   我的频道(有才显示)            │
-│   abc123… 🔒加密 所有者 3 台设备  │
-│ ┌ 设备频道 ───────────────────┐ │
-│ │ 多台设备之间长期同步           │ │
-│ │ [ 新建频道 ]   [ 加入频道 ]   │ │
-│ └────────────────────────────┘ │
-└──────────────────────────────────┘
-```
+主页右上角提供外观菜单，右下角显示前端和后端的 tag 与短 commit hash 及上海时间的构建时间；无法取得 tag 时如实显示「未标记」。
 
 | 操作 | 结果 |
 |---|---|
 | 快速分享(输入文本、拖入、粘贴、选择、相册、拍照) | 先在首页编辑临时文本并收集文件;点「创建临时分享」后建立加密草稿并带入内容;点「完成分享」后生成链接与二维码 |
-| 新建频道 | 登录后创建，自动成为该频道所有者；可选择是否端到端加密，默认启用；设备数、TTL、受限下载次数和上传权限仍用同一频道模型 |
+| 新建频道 | 登录后创建，自动成为该频道所有者；可选择是否端到端加密，默认启用；成员人数上限、TTL、受限下载次数和上传权限仍用同一频道模型 |
 | 加入频道 | 扫码或粘贴链接 → 加入预览 → 加入 |
-| 我的频道 | 点一行进入；垃圾桶从当前账号/访客资源清单移除，**不会删除频道**，需二次确认；账号清单移除会同步到其他设备 |
+| 我的频道 | 点一行进入；垃圾桶从当前账号资源清单移除，**不会删除频道**，需二次确认；账号清单移除会同步到其他设备 |
 | 账号与同步 | 用户名密码注册或登录;本地频道/分享凭据在 Worker 加密后同步,另一台设备登录后恢复;退出时撤销会话 |
 
+登录/注册页是居中的单列卡片（标题与标语在上，卡片在下）；创建账号需要再输入一次密码确认，两次不一致时就地提示并禁用提交。账号设置是左侧导航 + 右侧单页（个人资料 / 我的设备 / 安全 / 空间邀请 / 同步与登录；手机上导航变为顶部横向页签），结果统一用 toast 反馈，设备重命名就地编辑，移除设备与退出登录需确认。
+
 账号密码不提供找回流程。忘记密码会导致账号保险库无法解密;界面需在注册区域明确提示。本机记住登录通过 IndexedDB 保存 session 和不可导出的保险库 CryptoKey，刷新后恢复身份；退出或设备被撤销后清除。
 
-未登录访问首页时先显示注册/登录页；收到的频道或分享链接保持访客入口。频道加入页按当前规则显示密码输入或登录提示。右上角频道设置集中管理加入方式、陌生人开关、频道密码、成员角色、邀请与撤销，不另设权限入口。
+未登录访问首页时先显示注册/登录页；收到的分享链接任何人可读；收到的频道链接要求登录，未登录先显示登录页，登录后继续加入。频道加入页按当前规则显示密码输入。右上角频道设置集中管理加入方式（登录后持链接加入 / 仅受邀账号）、频道密码、成员角色、邀请与撤销，不另设权限入口。
 
 | 路由 | 页面 |
 |---|---|
@@ -148,7 +133,7 @@ WebDrop 是**暂存区**,频道工作区:聊天按 thread 展示，文件按 thr
 
 ### 6.4.1 便捷分享
 
-Share 是独立的只读发布资源，不创建频道成员、threads 或席位。创建者在草稿中添加内容和设置，明确确认后封存；服务端清除 owner_hash，前端丢弃管理密钥，此后只有读取入口。访客打开分享链接直接读取加密清单，下载受限文件时计次数，不经过频道加入流程。详见 protocol.md §15。
+Share 是独立的只读发布资源，不创建频道成员或 threads。创建者在草稿中添加内容和设置，明确确认后封存；服务端清除 owner_hash，前端丢弃管理密钥，此后只有读取入口。访客打开分享链接直接读取加密清单，下载受限文件时计次数，不经过频道加入流程。详见 protocol.md §15。
 
 ### 6.5 频道 thread、文件管理与聊天
 
@@ -156,7 +141,7 @@ Share 是独立的只读发布资源，不创建频道成员、threads 或席位
 
 左栏按 thread 显示虚拟文件夹与文件。可以创建/重命名 thread、创建/重命名文件夹、多选文件并移动到当前 thread 的文件夹。文件预览仍使用中央预览区;消息不混入文件列表。手机上 thread 和文件树可横向/纵向收缩,聊天输入固定在文件列表下方、上传动作栏上方。
 
-thread 名、文件夹名和移动操作使用同一套 CONTROL 日志条目同步；端到端加密开启时元数据是密文，关闭时服务端可见。两种传输选项共享相同的线程和目录模型。GATED 文件通过独立加密目录显示名称和归属，内容仅在显式操作后读取；没有目录记录的旧文件仍显示通用占位。
+频道名、文件夹名和移动操作通过后端结构接口管理，其他设备收到通知后重新读取。文件名称和类型仍通过加密资源元数据同步，GATED 内容仅在显式操作后读取。
 
 其他弹层:
 
@@ -165,8 +150,8 @@ thread 名、文件夹名和移动操作使用同一套 CONTROL 日志条目同
 | 条目详情 | 手机为底部抽屉,电脑为内联预览区;内容一致 |
 | 扫码加入 | 相机识别二维码(浏览器自带 `BarcodeDetector`,不支持或无权限时退回「粘贴链接」)→ 加入预览(模式、权限)→ 加入后进入该频道 |
 | 写文本 | 抽屉,`Ctrl+Enter` 发送;首页上用于快速分享 |
-| 频道设置 | 顶栏齿轮打开设置面板;所有者可修改名称、席位、成员上传、保留时间和受限文件下载次数 |
-| 设备管理 | 设备面板显示已加入席位数;设备可重命名,所有者可重命名任意设备并移除其他设备 |
+| 频道设置 | 顶栏齿轮打开设置面板;所有者可修改名称、成员人数上限、成员上传、保留时间和受限文件下载次数 |
+| 设备管理 | 设备面板分别显示成员人数与已连接设备;成员人数按账号去重,同一账号可在多台设备登录;设备可重命名,所有者可移除任意设备 |
 
 扫到的链接含密钥,只放在内存里,不写日志、不持久化。
 
@@ -249,8 +234,8 @@ thread 名、文件夹名和移动操作使用同一套 CONTROL 日志条目同
 
 ### 7.5 频道文件预览与下载限制
 
-- 新上传文件默认允许单帧内容直接随频道同步。加入频道的访客可直接看到文件名、类型、大小；PNG 等图片和 TXT 等文本可直接预览,不消耗下载次数。文件名与类型仍只存在于加密帧中。
-- 超出单帧容量的文件保持 GATED,列表不自动读取内容。访客主动打开预览时才取回文件,并消耗一次下载次数;取回后显示解密出的文件名、类型和大小。EXE 等不支持内联预览的类型仍提供下载。
+- 新上传文件默认允许单帧内容直接随频道同步。加入频道的成员可直接看到文件名、类型、大小；PNG 等图片和 TXT 等文本可直接预览,不消耗下载次数。文件名与类型仍只存在于加密帧中。
+- 超出单帧容量的文件保持 GATED,列表不自动读取内容。成员主动打开预览时才取回文件,并消耗一次下载次数;取回后显示解密出的文件名、类型和大小。EXE 等不支持内联预览的类型仍提供下载。
 - 上传者可关闭直接预览并为文件设置下载次数上限。
 - 设备标签优先显示浏览器提供的机型和系统版本,例如「Pixel 9 (Android 16) · A1B2C3D4」「Windows 11 · 1234ABCD」。浏览器没有暴露具体机型时显示能识别的平台名称;保留端点短标识以区分同型号设备。
 
@@ -258,7 +243,7 @@ thread 名、文件夹名和移动操作使用同一套 CONTROL 日志条目同
 
 | 码 | 页面 |
 |---|---|
-| `seats_full` | 加入预览页:「席位已满」,告知联系所有者 |
+| `members_full` | 加入预览页:「成员人数已满」,告知联系所有者 |
 | `not_joined`(被释放) | 频道页整体替换为「你已被移出此频道」 |
 | `not_found` / `gone` | 「频道不存在或已过期」 |
 | `rate_limited` | Toast,带重试倒计时 |
@@ -331,11 +316,19 @@ thread 名、文件夹名和移动操作使用同一套 CONTROL 日志条目同
 
 ## 13. 空间、频道与频道分组
 
-界面层级统一为「空间 → 频道分组（可选）→ 频道 → 聊天与文件夹」。原顶层频道对用户称为空间，原 thread 对用户称为频道。新建空间自动创建“常规”频道。空间负责成员、邀请、设备席位和加密边界；频道分组只组织导航，不改变权限或加密密钥。
+界面层级统一为「空间 → 频道分组（可选）→ 频道 → 聊天与文件夹」。原顶层频道对用户称为空间，原 thread 对用户称为频道。新建空间自动创建“常规”频道。空间负责成员、邀请、成员人数上限和加密边界；账号内设备不重复计入人数，设备只是账号的属性，只在账号设置里管理。频道分组只组织导航，不改变权限或加密密钥。
 
-左侧上段显示账号与空间列表，下段按分组展示频道。支持新建/重命名分组、折叠分组、在分组内新建频道、将已有频道移入其他分组或移回未分组。旧 thread 自动作为未分组频道展示。中间显示当前频道聊天，右侧显示当前频道文件夹和文件。
+桌面最左是 64px 的空间窄栏（每个空间一个首字方块，当前空间反色；下方是新建空间与加入空间），其右 240px 的频道列：顶部是空间名与加密状态（点击打开空间设置），下面按分组展示频道，分组标题小号灰字，悬停才显示 + 与 ⋯，频道行 32px、选中为整行淡底；便签并入频道列底部。账号卡片贴在左下角横跨两栏。手机上这些都收进左侧抽屉：顶部是横向一排空间方块，其下是空间名栏与频道列表。支持新建/重命名分组、折叠分组、在分组内新建频道、将已有频道移入其他分组或移回未分组。旧 thread 自动作为未分组频道展示。中间显示当前频道聊天，右侧显示当前频道文件夹和文件。
 
-空间设置集中管理成员、邀请和空间权限；频道管理提供名称与所属分组。分组名及归属通过已有加密 CONTROL 日志同步，刷新与其他设备保持一致。协议/API 内部保留 channels/thread_id 等标识，避免因界面术语变更重建已有数据。
+空间设置集中管理成员、邀请和空间权限；频道管理提供名称与所属分组。分组名及归属由后端持久化并通过通知刷新，刷新与其他设备保持一致。协议/API 内部保留 channels/thread_id 等标识，避免因界面术语变更重建已有数据。
+
+### 13.1 成员栏、邀请与通知
+
+右侧栏顶部是「文件 / 成员 n」页签，默认文件；顶栏的人数按钮直接打开成员页，空间主还有一个 ＋ 直接打开邀请弹窗。手机上没有页签，「文件」「成员」放在左侧抽屉里。
+
+成员页以用户为单位，按 Discord 的分组排列：在线 — n、离线 — n、待接受 — n（仅空间主可见，有「撤销」）。每行头像、昵称（有昵称时下方小字显示用户名），空间主带「空间主」标签；一个用户有多台设备时小字显示「在线设备/设备数 台设备在线」。**设备不再单独列出，只是用户的属性。**在线状态与设备数由后端按账号统计（`GET /channels/{id}/members` 的 `online`、`devices`、`online_devices`，在线 = 该账号在本频道有活动订阅），前端在成员页可见期间每 8 秒读取一次，不改动订阅流。空间主在页头有醒目的「＋ 邀请成员」，成员行悬停出现「移除」（需确认）。邀请与成员管理不再放在空间设置里，设置里只留一句指引。
+
+邀请弹窗只收用户名；成功、撤销、移除、失败都弹 toast。toast 在右下角，4 秒消失（带操作按钮的 10 秒），最多 4 条，成功 / 失败 / 提示用左侧色条区分，`aria-live`。被邀请方登录后每 8 秒轮询账号邀请，出现新邀请就弹「xxx 邀请你加入 yyy [接受]」，点「接受」直接加入并进入空间；账号设置里的邀请收件箱同样显示空间名与邀请人。空间名与邀请人放在邀请 payload 的加密内容里（`ChannelGrant.name / invitedBy`，均为可选字段），服务端不可见；旧邀请没有这两个字段时回退为「空间 + ID 前 8 位」。
 
 ## 14. 文件管理器交互
 
@@ -343,15 +336,19 @@ thread 名、文件夹名和移动操作使用同一套 CONTROL 日志条目同
 
 右键文件提供预览、下载、复制名称、移动和删除；文件夹提供打开和重命名；空白区域提供上传、新建文件夹、全选。菜单和悬停卡通过 portal 挂载到 body，贴近指针且限制在视口内，支持 Escape、外部点击和键盘导航。
 
-文件可拖入当前频道的文件夹或面包屑目录，多选文件可一起移动；跨空间/频道的内部拖放拒绝。外部文件可拖入指定文件夹上传。内部拖拽移动仅追加目录控制记录，不重新加密或拉取文件。
+文件可拖入当前频道的文件夹或面包屑目录，多选文件可一起移动；跨空间/频道的内部拖放拒绝。外部文件可拖入指定文件夹上传。内部拖拽移动由后端更新资源归属，不重新加密或拉取文件。
 
 悬停卡延迟显示名称、类型、大小、时间；已同步且非 GATED 的小图片/文本可显示缩略预览。GATED、上传中或校验失败的文件不会自动取内容，悬停不消耗下载次数。右侧文件区与聊天之间可拖动分隔条调整宽度，分隔条也支持键盘左右键。
 
 ## 15. 频道中的文件消息与发送者
 
-聊天时间线同时显示文本和已发布的文件，文件消息使用头像、发送者名称、时间和文件卡片，卡片提供预览和下载。当前账号发出的消息靠右，其他人的消息靠左；没有头像时显示名称首字。上传中显示进度和状态，受限文件不自动加载内容或媒体缩略图。
+聊天时间线采用 Discord 式布局：所有消息靠左，同一条左边线，左侧头像、右侧「名称 + 时间」一行与占满宽度的正文，不再区分自己和他人。同一发送者 5 分钟内连发的消息合并，只缩进对齐，悬停时在头像位置显示时间；悬停整行有淡底，右上角出现删除。文件消息是 360px 以内的文件卡片（图标、名称、大小与类型，右侧预览与下载）；没有头像时显示名称首字。受限文件不自动加载内容或媒体缩略图。
 
-发送者名称优先使用发送时的个人名称，回退固定用户名；设备名保留在提示中。姓名和头像快照随空间加密日志同步，其他账号和设备刷新后仍能看到原上传者。旧记录没有发送者快照时回退设备来源，不推测为当前用户。
+输入区是整体圆角框（左 + 附件、中间自增高输入、右发送），占位文案「给 #频道名 发消息」，Enter 发送、Shift+Enter 换行（输入法组合中不触发）。
+
+**乐观发送**：点发送的同一帧就清空输入框并在时间线底部画出消息（半透明，aria-busy），后台再加密上传，不等后端；可以连续快速发送。worker 发布真实条目时带回 localId，在同一次状态更新里替换占位项，不闪烁、不重复。失败时占位项保留原文本并显示「发送失败 · 重试」，可删除；离线沿用本机发送队列。文件同理：确认上传选项后卡片立刻出现并显示进度。
+
+发送者名称与头像从后端账号资料读取，回退固定用户名。资源作者由后端记录，昵称修改后其他设备同步更新展示。没有账号归属（未登录访客）时统一显示「访客」；界面里不再展示设备名，设备只在账号设置的「我的设备」里管理。
 
 头像缩略图在 Worker 内生成，最大 64×64、编码后不超过 8 KB，仅使用 PNG/JPEG/WebP data URL；不使用第三方头像链接。圆形头像使用专门的 --radius-avatar token，消息气泡仍遵守现有圆角规范。
 

packages/core/README.md

@@ -51,7 +51,6 @@ ws.onmessage = async (m) => {
 | 加密成帧、padding、IV、AAD | 发送队列(IndexedDB)、失败重发 |
 | 解密、完整性校验、乱序/重复/篡改处理 | 把事件渲染成界面 |
 | 链接生成与解析、降级防御 | 持久化链接和**终端密钥** |
-| 设备名加解密 | 复制、下载(把流写到文件)、预览 |
 | 日志记录解析 | **Cap 验证码**(见下文) |
 
 ## API
@@ -67,7 +66,6 @@ ws.onmessage = async (m) => {
 | `session.link(origin, 'member' \| 'owner')` | 生成分享链接 |
 | `session.verifyChannelInfo({ id, mode })` | 核对服务端返回的频道信息,不一致抛 `ModeMismatchError` / `LinkError` |
 | `session.id` / `.mode` / `.role` / `.endpointSecret` / `.endpointHash` | 只读属性 |
-| `session.deviceName` | 设置后,加密的条目元数据里会带上设备名 |
 | `session.dispose()` | 尽力清零密钥材料(JS 无法保证擦除) |
 
 ### 发送
@@ -91,7 +89,7 @@ ws.onmessage = async (m) => {
 | `snapshot` | 快照必须是单帧(约 1 MiB 以内),不能 GATED |
 | `itemId` | 重试和续传必须复用同一个 id |
 | `fromFrame` | 上传断点续传:从第 k 帧开始产出(字节与完整加密完全相同)。仅支持 `Blob` / `Uint8Array` |
-| `ts`, `dev` | 覆盖时间戳和设备名 |
+| `ts` | 覆盖时间戳 |
 
 **GATED 的判断**:来源长度已知时创建计划时就确定;来源是流时,要产出第 0 帧之后 `plan.gated` 和 `frame0Headers` 才确定,请在拿到第 0 帧后再读取。
 
@@ -131,13 +129,12 @@ const { complete, nextIndex, meta } = await result;
 | 调用 | 说明 |
 |---|---|
 | `parseLogRecords(bytes)` / `parseLogRecord(bytes)` | 解析 `GET /log` 的响应或一条 WebSocket 消息 |
-| `session.sealLabel(name)` / `session.openLabel(blob, endpointHash)` | 设备名(`PUT /seats/me` 的请求体 / 席位列表里的 `label`) |
 | `parseLink(url)` / `buildLink(origin, parts)` | 链接 |
 | `splitEnvelopes(stream)` | 把「封装首尾相接」的字节流切成一个个封装 |
 
 ## 必须注意的几点
 
-**1. 终端密钥必须持久化。** `session.endpointSecret`(32 字节)标识「这台设备在这个频道里」,服务端按它占用席位。不持久化的话,每次打开链接都会占用一个新席位。用 IndexedDB 保存,下次 `open(link, { endpointSecret })` 传回来。
+**1. 终端密钥只用于便捷分享。** `session.endpointSecret`(32 字节)标识「这个终端」,便捷分享的创建者与读者靠它登记和续传；频道与空间只凭账号会话鉴权,不使用它。分享读者不持久化的话,每次打开链接都会登记一个新访客终端,用 IndexedDB 保存。
 
 **2. Worker。** `ChannelSession` 实例不能跨线程传递(它持有 `CryptoKey` 和闭包)。在 Worker 里用链接和 `endpointSecret` 重建它,主线程只传链接、帧字节和事件。
 
@@ -167,10 +164,10 @@ npm run vectors:check  # 校验 test-vectors/vectors.json 是最新的
 | 文件 | 内容 |
 |---|---|
 | `vectors.test.ts` | 逐字节复现 `test-vectors/` 里 node:crypto 独立生成的全部向量,含 17 个负例 |
-| `session.test.ts` | 创建、链接、角色、降级防御、收发、设备名、raw 模式、条目计划 |
+| `session.test.ts` | 创建、链接、角色、降级防御、收发、raw 模式、条目计划 |
 | `reader.test.ts` | 日志记录、重放、乱序、缺帧、FINAL 冲突、标志变化、模式隔离 |
 | `stream.test.ts` | 任意切分的字节流、流式解密、篡改/拼接/丢帧/截断、断点续传 |
 | `properties.test.ts` | 每个字节每一位的篡改、padding 档位、随机往返、来源块边界对齐、性能底线 |
-| `e2e.test.ts` | 真实服务端:HTTP、WebSocket、大文件、下载上限、上传与下载续传、设备名 |
+| `e2e.test.ts` | 真实服务端:HTTP、WebSocket、大文件、下载上限、上传与下载续传 |
 
 另外对测试集做过**变异检验**:故意在实现里注入 10 类典型错误(AAD 少一字节、跳过零填充检查、去掉模式/条目 id 校验、base64 不查规范性、分块边界差一、IV 不含帧序号、重复帧不比较、FINAL 后不拒绝、链接不拒绝查询串密钥),测试都能变红。其中「分块边界差一」最初漏网,说明测试有缺口,已补上专门的边界对齐用例。

packages/core/src/constants.ts

@@ -38,11 +38,7 @@ export const Labels = {
 
 /** AAD 前缀。 */
 export const AAD_FRAME = 'WD1';
-export const AAD_LABEL = 'WD1L';
 
-/** 设备名总长上限(iv + 密文 + tag),与服务端 MaxSeatLabelBytes 一致。 */
-export const MAX_LABEL_BYTES = 256;
-export const LABEL_IV_SIZE = 12;
 
 export const POW_NONCE_SIZE = 8;
 

packages/core/src/index.ts

@@ -13,6 +13,7 @@
  */
 
 export { ChannelSession, openLink } from './session.js';
+export { parseEnvelope } from './frame.js';
 export type {
   AuthRole,
   ChannelSettings,
@@ -40,6 +41,8 @@ export { buildLink, parseLink } from './link.js';
 export type { LinkParts, ParsedLink } from './link.js';
 
 export { fromBase64Url, toBase64Url } from './bytes.js';
+export { contentEventPayload, frameManifestHash, generateSigningKeyPair, importSigningPublicKey, signStatement, verifyStatement } from './signatures.js';
+export type { ContentEventStatement } from './signatures.js';
 
 export { Flags, MAX_FRAME_DATA, PROTOCOL_VERSION } from './constants.js';
 export type { ChannelMode, ItemKind } from './constants.js';

packages/core/src/reader.ts

@@ -3,6 +3,7 @@ import { concat, equalBytes, tryDecodeUtf8, toBase64Url, type Bytes } from './by
 import { IntegrityError, type IntegrityReason } from './errors.js';
 import { openFrame, parseEnvelope, type Envelope } from './frame.js';
 import { sha256 } from './kdf.js';
+import { frameManifestHash } from './signatures.js';
 import { decodeFirstFrame, type ItemMeta } from './item.js';
 import { parseLogRecord, type LogRecord, type RemovedReason } from './log.js';
 
@@ -29,6 +30,8 @@ export interface ReceivedItem {
   complete: boolean;
   /** 到第一个缺口为止已收到的内容。大文件请改用 decryptItemStream,不要在这里缓冲。 */
   content: Bytes;
+  /** SHA-256 manifest over the complete ciphertext envelopes in frame-index order. */
+  ciphertextManifestHash?: Bytes;
 }
 
 export type ItemEvent =
@@ -104,7 +107,7 @@ export class ItemReader {
 
     const itemId = toBase64Url(env.itemId);
     try {
-      return await this.#accept(env, itemId, seq);
+      return await this.#accept(env, itemId, seq, Uint8Array.from(envelope));
     } catch (e) {
       if (!(e instanceof IntegrityError)) throw e;
       this.#open.delete(itemId);
@@ -118,7 +121,7 @@ export class ItemReader {
     this.#done.delete(itemId);
   }
 
-  async #accept(env: Envelope, itemId: string, seq: number | undefined): Promise<ItemEvent[]> {
+  async #accept(env: Envelope, itemId: string, seq: number | undefined, envelope: Bytes): Promise<ItemEvent[]> {
     const isEncFrame = (env.flags & Flags.Enc) !== 0;
     // 降级防御:enc 会话只接受认证过的 enc 帧,服务端不能注入明文帧;raw 会话反之
     if (isEncFrame !== (this.#ctx.mode === 'enc')) throw new IntegrityError('wrong_mode');
@@ -139,7 +142,7 @@ export class ItemReader {
     }
 
     // 重复帧:内容必须逐字节相同,相同则视为重放,不产生事件
-    const digest = await sha256(env.payload);
+    const digest = await sha256(envelope);
     const dup = state?.frames.get(env.frameIndex);
     if (dup) {
       if (!equalBytes(dup.digest, digest)) throw new IntegrityError('duplicate_mismatch');
@@ -186,6 +189,9 @@ export class ItemReader {
       content: concat(...parts),
     };
     if (state.meta) item.meta = state.meta;
+    if (complete) item.ciphertextManifestHash = Uint8Array.from(await frameManifestHash(
+      Array.from({ length: state.finalIndex! + 1 }, (_, index) => state!.frames.get(index)!.digest),
+    ));
 
     if (complete) {
       this.#open.delete(itemId);

packages/core/src/session.ts

@@ -1,6 +1,6 @@
-import { AAD_LABEL, ID_SIZE, KEY_SIZE, LABEL_IV_SIZE, MAX_LABEL_BYTES, TAG_SIZE, type ChannelMode } from './constants.js';
-import { concat, fromBase64Url, randomBytes, toBase64Url, tryDecodeUtf8, utf8, wipe, type Bytes } from './bytes.js';
-import { CapabilityError, IntegrityError, LimitError, LinkError, ModeMismatchError } from './errors.js';
+import { ID_SIZE, KEY_SIZE, type ChannelMode } from './constants.js';
+import { randomBytes, toBase64Url, utf8, wipe, type Bytes } from './bytes.js';
+import { CapabilityError, LinkError, ModeMismatchError } from './errors.js';
 import { encodeEnvelope, sealFrame } from './frame.js';
 import { deriveChannelKeys, deriveItemKey, deriveOwnerToken, sha256, type ChannelKeys } from './kdf.js';
 import { buildLink, parseLink, type ParsedLink } from './link.js';
@@ -13,9 +13,8 @@ export type AuthRole = 'read' | 'write' | 'owner';
 /** 频道设置,字段名与 API 一致(snake_case)。 */
 export interface ChannelSettings {
   join_policy?: 'open' | 'invite';
-  allow_guests?: boolean;
   name?: string;
-  seats?: number;
+  max_members?: number;
   members_can_upload?: boolean;
   delete_policy?: 'owner_only' | 'own' | 'anyone';
   ttl_seconds?: number;
@@ -92,6 +91,8 @@ interface SessionInit {
  * JS 无法保证这些内存被真正擦除。调用 dispose() 只能尽力清零。
  */
 export class ChannelSession {
+  /** Applications may supply independently authorized object keys instead of the space root. */
+  objectKeyResolver?: (itemId: string) => Promise<CryptoKey>;
   readonly id: string;
   readonly idBytes: Bytes;
   readonly mode: ChannelMode;
@@ -247,6 +248,7 @@ export class ChannelSession {
 
   /** 一个条目的 AES-GCM 密钥,带缓存。 */
   itemKey(itemId: Uint8Array): Promise<CryptoKey> {
+    if (this.objectKeyResolver) return this.objectKeyResolver(toBase64Url(itemId));
     if (!this.#keys) throw new CapabilityError('enc');
     const cacheKey = toBase64Url(itemId);
     let key = this.#itemKeys.get(cacheKey);
@@ -328,68 +330,6 @@ export class ChannelSession {
     return decryptItemStream(this.#readerContext, source, opts);
   }
 
-  // ───────────────────────── 设备名(protocol §10) ─────────────────────────
-
-  /**
-   * 加密设备名,作为席位名称 PUT 请求体。格式:iv(12) ‖ AES-GCM(K_label, 名称) ‖ tag(16),
-   * AAD = "WD1L" ‖ channel_id ‖ endpoint_hash。raw 模式下设备名是明文 UTF-8。
-   * @param opts.endpointHash 指定目标席位;所有者可给其他终端重命名。
-   * @param opts.iv 仅用于测试向量,真实使用必须让库随机生成。
-   */
-  async sealLabel(name: string, opts: { iv?: Uint8Array; endpointHash?: Uint8Array | string } = {}): Promise<Bytes> {
-    const endpointHash = typeof opts.endpointHash === 'string'
-      ? fromBase64Url(opts.endpointHash, 32)
-      : opts.endpointHash ?? this.endpointHash;
-    if (!endpointHash || endpointHash.length !== 32) throw new RangeError('终端标识必须是 32 字节');
-    const plain = utf8(name);
-    if (this.mode === 'raw') {
-      if (plain.length > MAX_LABEL_BYTES) throw new LimitError('设备名过长');
-      return plain;
-    }
-    if (plain.length === 0) throw new RangeError('设备名不能为空');
-    if (plain.length + LABEL_IV_SIZE + TAG_SIZE > MAX_LABEL_BYTES) {
-      throw new LimitError(`设备名过长(最多 ${MAX_LABEL_BYTES - LABEL_IV_SIZE - TAG_SIZE} 字节 UTF-8)`);
-    }
-    const iv = opts.iv ?? randomBytes(LABEL_IV_SIZE);
-    const sealed = await globalThis.crypto.subtle.encrypt(
-      { name: 'AES-GCM', iv: iv as Bytes, additionalData: this.#labelAad(endpointHash), tagLength: 128 },
-      (this.#keys as ChannelKeys).labelKey,
-      plain,
-    );
-    return concat(iv, new Uint8Array(sealed));
-  }
-
-  /** 解密席位列表里某个终端的设备名。endpointHash 可以是 base64url 文本或字节。 */
-  async openLabel(blob: Uint8Array | string, endpointHash: Uint8Array | string): Promise<string> {
-    const raw = typeof blob === 'string' ? fromBase64Url(blob) : blob;
-    const hash = typeof endpointHash === 'string' ? fromBase64Url(endpointHash, 32) : endpointHash;
-    if (!raw || !hash) throw new IntegrityError('bad_envelope');
-
-    if (this.mode === 'raw') {
-      const text = tryDecodeUtf8(raw);
-      if (text === null) throw new IntegrityError('bad_meta');
-      return text;
-    }
-    if (raw.length < LABEL_IV_SIZE + TAG_SIZE + 1) throw new IntegrityError('bad_envelope');
-    try {
-      const plain = await globalThis.crypto.subtle.decrypt(
-        { name: 'AES-GCM', iv: raw.slice(0, LABEL_IV_SIZE), additionalData: this.#labelAad(hash), tagLength: 128 },
-        (this.#keys as ChannelKeys).labelKey,
-        raw.slice(LABEL_IV_SIZE),
-      );
-      const text = tryDecodeUtf8(new Uint8Array(plain));
-      if (text === null) throw new IntegrityError('bad_meta');
-      return text;
-    } catch (e) {
-      if (e instanceof IntegrityError) throw e;
-      throw new IntegrityError('auth_failed');
-    }
-  }
-
-  #labelAad(endpointHash: Uint8Array): Bytes {
-    return concat(utf8(AAD_LABEL), this.idBytes, endpointHash);
-  }
-
   // ───────────────────────── 清理 ─────────────────────────
 
   /** 尽力清零可以清零的字节并清空缓存。JS 无法保证擦除,这只是缩小暴露窗口。 */

packages/core/src/signatures.ts

@@ -0,0 +1,110 @@
+const SIGNATURE_MAGIC = new Uint8Array([0x57, 0x44, 0x53, 0x01]); // WDS\x01
+const MAX_KIND_BYTES = 64;
+const MAX_PAYLOAD_BYTES = 1_048_576;
+const source = (value: Uint8Array): ArrayBuffer => {
+  const copy = new Uint8Array(value.length);
+  copy.set(value);
+  return copy.buffer;
+};
+
+export interface ContentEventStatement {
+  spaceId: Uint8Array;
+  channelId: string;
+  username: string;
+  deviceId: string;
+  eventId: Uint8Array;
+  eventKind: string;
+  domain: 'chat' | 'files';
+  epoch: number;
+  itemId: Uint8Array;
+  frameCount: number;
+  manifestHash: Uint8Array;
+  targetItemId?: Uint8Array;
+}
+
+export function contentEventPayload(event: ContentEventStatement): Uint8Array {
+  const channel = new TextEncoder().encode(event.channelId.toLowerCase());
+  const username = new TextEncoder().encode(event.username.toLowerCase());
+  const device = new TextEncoder().encode(event.deviceId.toLowerCase());
+  const kind = new TextEncoder().encode(event.eventKind);
+  const target = event.targetItemId ?? new Uint8Array();
+  if (event.spaceId.length !== 16 || event.eventId.length !== 16 || event.itemId.length !== 16 || event.manifestHash.length !== 32
+      || target.length !== 0 && target.length !== 16 || !Number.isInteger(event.epoch) || event.epoch < 0
+      || !Number.isInteger(event.frameCount) || event.frameCount < 1 || event.frameCount > 65_536
+      || !/^[0-9a-f-]{36}$/.test(event.channelId.toLowerCase()) || !/^[0-9a-f-]{36}$/.test(event.deviceId.toLowerCase())
+      || !/^[a-z0-9_-]{3,32}$/.test(event.username.toLowerCase()) || !/^[a-z][a-z.\-]{0,31}$/.test(event.eventKind))
+    throw new TypeError('签名事件字段无效');
+  const bytes = new Uint8Array(16 + 1 + channel.length + 1 + username.length + 1 + device.length + 16 + 1 + kind.length + 1 + 4 + 16 + 4 + 32 + 1 + 16);
+  let offset = 0;
+  bytes.set(event.spaceId, offset); offset += 16;
+  bytes[offset++] = channel.length; bytes.set(channel, offset); offset += channel.length;
+  bytes[offset++] = username.length; bytes.set(username, offset); offset += username.length;
+  bytes[offset++] = device.length; bytes.set(device, offset); offset += device.length;
+  bytes.set(event.eventId, offset); offset += 16;
+  bytes[offset++] = kind.length; bytes.set(kind, offset); offset += kind.length;
+  bytes[offset++] = event.domain === 'chat' ? 1 : 2;
+  new DataView(bytes.buffer).setUint32(offset, event.epoch, false); offset += 4;
+  bytes.set(event.itemId, offset); offset += 16;
+  new DataView(bytes.buffer).setUint32(offset, event.frameCount, false); offset += 4;
+  bytes.set(event.manifestHash, offset); offset += 32;
+  bytes[offset++] = target.length === 0 ? 0 : 1;
+  if (target.length) bytes.set(target, offset);
+  return bytes;
+}
+
+export async function frameManifestHash(frameDigests: readonly Uint8Array[]): Promise<Uint8Array> {
+  if (frameDigests.length < 1 || frameDigests.length > 65_536 || frameDigests.some(digest => digest.length !== 32))
+    throw new RangeError('帧清单无效');
+  const bytes = new Uint8Array(8 + frameDigests.length * 36);
+  bytes.set([0x57, 0x44, 0x31, 0x4d]); // WD1M
+  new DataView(bytes.buffer).setUint32(4, frameDigests.length, false);
+  let offset = 8;
+  for (let index = 0; index < frameDigests.length; index++) {
+    new DataView(bytes.buffer).setUint32(offset, index, false); offset += 4;
+    bytes.set(frameDigests[index]!, offset); offset += 32;
+  }
+  return new Uint8Array(await crypto.subtle.digest('SHA-256', source(bytes)));
+}
+
+function signingBytes(kind: string, payload: Uint8Array): Uint8Array {
+  if (!/^[a-z][a-z0-9._-]{0,63}$/.test(kind)) throw new TypeError('签名类型无效');
+  if (payload.length > MAX_PAYLOAD_BYTES) throw new RangeError('签名内容过大');
+  const kindBytes = new TextEncoder().encode(kind);
+  if (kindBytes.length > MAX_KIND_BYTES) throw new RangeError('签名类型过长');
+  const bytes = new Uint8Array(SIGNATURE_MAGIC.length + 2 + kindBytes.length + 4 + payload.length);
+  let offset = 0;
+  bytes.set(SIGNATURE_MAGIC, offset); offset += SIGNATURE_MAGIC.length;
+  new DataView(bytes.buffer).setUint16(offset, kindBytes.length, false); offset += 2;
+  bytes.set(kindBytes, offset); offset += kindBytes.length;
+  new DataView(bytes.buffer).setUint32(offset, payload.length, false); offset += 4;
+  bytes.set(payload, offset);
+  return bytes;
+}
+
+export async function generateSigningKeyPair(extractable = false): Promise<CryptoKeyPair> {
+  return crypto.subtle.generateKey({ name: 'ECDSA', namedCurve: 'P-256' }, extractable, ['sign', 'verify']);
+}
+
+export async function signStatement(privateKey: CryptoKey, kind: string, payload: Uint8Array): Promise<Uint8Array> {
+  const signature = await crypto.subtle.sign(
+    { name: 'ECDSA', hash: 'SHA-256' }, privateKey, source(signingBytes(kind, payload)),
+  );
+  const bytes = new Uint8Array(signature);
+  if (bytes.length !== 64) throw new Error('签名格式无效');
+  return bytes;
+}
+
+export async function verifyStatement(
+  publicKey: CryptoKey, kind: string, payload: Uint8Array, signature: Uint8Array,
+): Promise<boolean> {
+  if (signature.length !== 64) return false;
+  return crypto.subtle.verify(
+    { name: 'ECDSA', hash: 'SHA-256' }, publicKey, source(signature), source(signingBytes(kind, payload)),
+  );
+}
+
+export async function importSigningPublicKey(key: JsonWebKey): Promise<CryptoKey> {
+  if (key.kty !== 'EC' || key.crv !== 'P-256' || !key.x || !key.y || key.d !== undefined)
+    throw new TypeError('签名公钥格式无效');
+  return crypto.subtle.importKey('jwk', key, { name: 'ECDSA', namedCurve: 'P-256' }, false, ['verify']);
+}

packages/core/src/stream.ts

@@ -3,6 +3,8 @@ import { equalBytes, type Bytes } from './bytes.js';
 import { IntegrityError } from './errors.js';
 import { MAX_ENC_PAYLOAD, openFrame, parseEnvelope, peekEnvelopeLength } from './frame.js';
 import { decodeFirstFrame, type ItemMeta } from './item.js';
+import { sha256 } from './kdf.js';
+import { frameManifestHash } from './signatures.js';
 import type { ReaderContext } from './reader.js';
 
 /** 字节队列:接收任意切分的块,按需取出前 n 个字节。 */
@@ -106,6 +108,8 @@ export interface ItemDecodeResult {
   nextIndex: number;
   /** 第 0 帧里的元数据;从中间帧续传时没有。 */
   meta: ItemMeta | undefined;
+  /** Present only for complete reads starting at frame zero. */
+  ciphertextManifestHash?: Bytes;
 }
 
 /**
@@ -125,8 +129,10 @@ export async function* decryptItemFrames(
   let flagsMask: number | undefined;
   let finalSeen = false;
   let meta: ItemMeta | undefined;
+  const frameDigests: Bytes[] = [];
 
   for await (const bytes of splitEnvelopes(source)) {
+    frameDigests.push(await sha256(bytes));
     const env = parseEnvelope(bytes);
 
     const isEnc = (env.flags & Flags.Enc) !== 0;
@@ -157,7 +163,8 @@ export async function* decryptItemFrames(
     if (data.length > 0) yield data;
   }
 
-  return { complete: finalSeen, nextIndex: expected, meta };
+  return { complete: finalSeen, nextIndex: expected, meta,
+    ...(finalSeen && (opts.fromIndex ?? 0) === 0 ? { ciphertextManifestHash: Uint8Array.from(await frameManifestHash(frameDigests)) } : {}) };
 }
 
 /** 把 decryptItemFrames 包成 ReadableStream,便于直接 pipe 到文件。 */

packages/core/test/e2e.test.ts

@@ -45,7 +45,8 @@ let dataDir = '';
 let base = '';
 let accountToken = '';
 function headersFor(session: ChannelSession, role: AuthRole): Record<string, string> {
-  return { ...session.authHeaders(role), ...(session.role === 'owner' ? { 'X-WD-Account': accountToken } : {}) };
+  // 频道只接受登录账号:测试里所有角色共用同一个账号,权限差异由角色令牌体现
+  return { ...session.authHeaders(role), 'X-WD-Account': accountToken };
 }
 
 beforeAll(async () => {
@@ -78,9 +79,12 @@ beforeAll(async () => {
   const verifier = crypto.getRandomValues(new Uint8Array(32));
   const keys = await crypto.subtle.generateKey({ name: 'ECDH', namedCurve: 'P-256' }, true, ['deriveBits']);
   const pubkey = await crypto.subtle.exportKey('jwk', keys.publicKey);
+  const signingKeys = await crypto.subtle.generateKey({ name: 'ECDSA', namedCurve: 'P-256' }, true, ['sign', 'verify']);
+  const signingPublicKey = await crypto.subtle.exportKey('jwk', signingKeys.publicKey);
   const encoded = (value: Uint8Array) => Buffer.from(value).toString('base64');
   const registered = await fetch(`${base}/api/v1/accounts`, { method: 'POST', headers: { 'Content-Type': 'application/json' }, body: JSON.stringify({
-    username: 'core_e2e', salt: encoded(crypto.getRandomValues(new Uint8Array(16))), verifier: encoded(verifier), vault: encoded(new Uint8Array(28)), public_key: JSON.stringify(pubkey),
+    username: 'core_e2e', salt: encoded(crypto.getRandomValues(new Uint8Array(16))), verifier: encoded(verifier), vault: encoded(new Uint8Array(28)),
+    public_key: JSON.stringify(pubkey), signing_public_key: JSON.stringify(signingPublicKey),
   }) });
   expect(registered.status).toBe(204);
   const session = await fetch(`${base}/api/v1/accounts/session`, { method: 'POST', headers: { 'Content-Type': 'application/json' }, body: JSON.stringify({ username: 'core_e2e', verifier: encoded(verifier) }) });
@@ -98,7 +102,7 @@ afterAll(async () => {
 const api = (path: string) => `${base}/api/v1${path}`;
 
 async function createChannel(opts: Parameters<typeof ChannelSession.create>[0] = {}) {
-  const created = await ChannelSession.create(opts);
+  const created = await ChannelSession.create({ ...opts, settings: { name: 'Core E2E', ...opts.settings } });
   const res = await fetch(api('/channels'), {
     method: 'POST',
     headers: { ...created.request.headers, 'X-WD-Account': accountToken, 'Content-Type': 'application/json' },
@@ -111,7 +115,7 @@ async function createChannel(opts: Parameters<typeof ChannelSession.create>[0] =
 }
 
 async function joinChannel(session: ChannelSession, role: AuthRole = 'read') {
-  const res = await fetch(api(`/channels/${session.id}/seats`), { method: 'POST', headers: headersFor(session, role) });
+  const res = await fetch(api(`/channels/${session.id}/join`), { method: 'POST', headers: headersFor(session, role) });
   expect(res.status, await res.clone().text()).toBe(200);
 }
 
@@ -142,7 +146,7 @@ function subscribe(session: ChannelSession, role: AuthRole, until: (events: Item
   const h = headersFor(session, role);
   const protocols = ['wd.v1', `wd.role.${role}`, `wd.ep.${h['X-WD-Endpoint']!}`];
   if (h.Authorization) protocols.push(`wd.auth.${h.Authorization.replace('Bearer ', '')}`);
-  if (session.role === 'owner') protocols.push(`wd.account.${accountToken.replace(/\+/g, '-').replace(/\//g, '_').replace(/=+$/, '')}`);
+  protocols.push(`wd.account.${accountToken.replace(/\+/g, '-').replace(/\//g, '_').replace(/=+$/, '')}`);
 
   const ws = new WebSocket(`${base.replace('http', 'ws')}/api/v1/channels/${session.id}/ws?from=${from}`, protocols);
   ws.binaryType = 'arraybuffer';
@@ -387,38 +391,6 @@ suite('端到端(真实服务端)', () => {
     expect(Buffer.compare(concatAll([part1.bytes, part2]), content)).toBe(0);
   }, 60_000);
 
-  it('设备名:成员加密上传,所有者在席位列表里解开', async () => {
-    const owner = await createChannel();
-    const member = await ChannelSession.open(owner.link(ORIGIN));
-    await joinChannel(member, 'read');
-
-    const blob = await member.sealLabel('我的 iPhone');
-    const put = await fetch(api(`/channels/${owner.id}/seats/me`), {
-      method: 'PUT',
-      headers: { ...headersFor(member, 'read'), 'Content-Type': 'application/octet-stream' },
-      body: blob,
-    });
-    expect(put.status).toBe(204);
-
-    const res = await fetch(api(`/channels/${owner.id}/seats`), { headers: headersFor(owner, 'owner') });
-    const seats = (await res.json()) as Array<{ endpoint_hash: string; label?: string }>;
-    const mine = seats.find((s) => s.endpoint_hash === toBase64Url(member.endpointHash))!;
-    expect(await owner.openLabel(mine.label!, mine.endpoint_hash)).toBe('我的 iPhone');
-    // 服务端存的是密文
-    expect(Buffer.from(mine.label!, 'base64url').toString('utf8')).not.toContain('iPhone');
-  });
-
-  it('最长的设备名(228 字节)也被服务端接受', async () => {
-    const owner = await createChannel();
-    const blob = await owner.sealLabel('x'.repeat(228));
-    const put = await fetch(api(`/channels/${owner.id}/seats/me`), {
-      method: 'PUT',
-      headers: { ...headersFor(owner, 'owner'), 'Content-Type': 'application/octet-stream' },
-      body: blob,
-    });
-    expect(put.status).toBe(204);
-  });
-
   it('raw 频道:匿名成员无需令牌即可读取,服务端看得到明文', async () => {
     const owner = await createChannel({ mode: 'raw' });
     const member = await ChannelSession.open(owner.link(ORIGIN));
@@ -445,7 +417,7 @@ suite('端到端(真实服务端)', () => {
     const member = await ChannelSession.open(owner.link(ORIGIN));
     await joinChannel(member, 'read');
 
-    const res = await fetch(api(`/channels/${owner.id}/seats`), { headers: { ...headersFor(member, 'read') } });
+    const res = await fetch(api(`/channels/${owner.id}/settings`), { method: 'PATCH', headers: { ...headersFor(member, 'read'), 'Content-Type': 'application/json' }, body: '{}' });
     expect(res.status).toBe(403);
     expect(() => headersFor(member, 'owner')).toThrow();
   });

packages/core/test/session.test.ts

@@ -3,7 +3,6 @@ import { fromBase64Url, toBase64Url } from '../src/bytes.js';
 import {
   CapabilityError,
   ChannelSession,
-  IntegrityError,
   LimitError,
   LinkError,
   ModeMismatchError,
@@ -61,8 +60,8 @@ describe('创建 enc 频道', () => {
   });
 
   it('设置原样放进请求体', async () => {
-    const { request } = await ChannelSession.create({ settings: { seats: 3, delete_policy: 'anyone' } });
-    expect(request.body.settings).toEqual({ seats: 3, delete_policy: 'anyone' });
+    const { request } = await ChannelSession.create({ settings: { max_members: 3, delete_policy: 'anyone' } });
+    expect(request.body.settings).toEqual({ max_members: 3, delete_policy: 'anyone' });
   });
 });
 
@@ -281,39 +280,6 @@ describe('发送和接收(enc)', () => {
   });
 });
 
-describe('设备名', () => {
-  it('所有者能读出成员的设备名,其他人换个终端哈希读不出', async () => {
-    const { session: owner } = await ChannelSession.create();
-    const member = await ChannelSession.open(owner.link(ORIGIN));
-    const blob = await member.sealLabel('办公室电脑');
-
-    expect(await owner.openLabel(blob, member.endpointHash)).toBe('办公室电脑');
-    expect(await owner.openLabel(toBase64Url(blob), toBase64Url(member.endpointHash))).toBe('办公室电脑');
-    await expect(owner.openLabel(blob, owner.endpointHash)).rejects.toThrowError(IntegrityError);
-  });
-
-  it('每次加密使用新的随机 IV', async () => {
-    const { session } = await ChannelSession.create();
-    const a = await session.sealLabel('x');
-    const b = await session.sealLabel('x');
-    expect(toHex(a.slice(0, 12))).not.toBe(toHex(b.slice(0, 12)));
-  });
-
-  it('篡改后解不开', async () => {
-    const { session } = await ChannelSession.create();
-    const blob = await session.sealLabel('abc');
-    blob[blob.length - 1]! ^= 1;
-    await expect(session.openLabel(blob, session.endpointHash)).rejects.toThrowError(IntegrityError);
-  });
-
-  it('raw 模式下设备名是明文', async () => {
-    const { session } = await ChannelSession.create({ mode: 'raw' });
-    const blob = await session.sealLabel('plain');
-    expect(new TextDecoder().decode(blob)).toBe('plain');
-    expect(await session.openLabel(blob, session.endpointHash)).toBe('plain');
-  });
-});
-
 describe('raw 模式往返', () => {
   it('单帧:保留统一元数据,没有加密标志', async () => {
     const { session: owner } = await ChannelSession.create({ mode: 'raw' });

packages/core/test/signatures.test.ts

@@ -0,0 +1,43 @@
+import { describe, expect, it } from 'vitest';
+import { fromBase64Url } from '../src/bytes.js';
+import { contentEventPayload, frameManifestHash, generateSigningKeyPair, signStatement, verifyStatement } from '../src/signatures.js';
+import { h, vectors } from './helpers.js';
+
+describe('协议签名原语', () => {
+  it('跨语言固定向量可以验签,且类型和负载均受签名保护', async () => {
+    const fixture = vectors.signatures;
+    const publicKey = await crypto.subtle.importKey('jwk', {
+      kty: 'EC', crv: 'P-256', x: fixture.x, y: fixture.y, ext: true,
+    }, { name: 'ECDSA', namedCurve: 'P-256' }, false, ['verify']);
+    const payload = h(fixture.payload);
+    const signature = h(fixture.signature);
+    expect(await verifyStatement(publicKey, fixture.kind, payload, signature)).toBe(true);
+    expect(await verifyStatement(publicKey, 'chat.edit', payload, signature)).toBe(false);
+    payload[0] = payload[0]! ^ 1;
+    expect(await verifyStatement(publicKey, fixture.kind, payload, signature)).toBe(false);
+    expect(await verifyStatement(publicKey, fixture.kind, h(fixture.payload), signature.subarray(1))).toBe(false);
+    expect(fromBase64Url(fixture.x)).toHaveLength(32);
+  });
+
+  it('浏览器签名可验证,篡改被拒绝', async () => {
+    const pair = await generateSigningKeyPair();
+    expect(pair.privateKey.extractable).toBe(false);
+    const payload = new TextEncoder().encode('signed command bytes');
+    const signature = await signStatement(pair.privateKey, 'workspace.channel.create', payload);
+    expect(signature).toHaveLength(64);
+    expect(await verifyStatement(pair.publicKey, 'workspace.channel.create', payload, signature)).toBe(true);
+    expect(await verifyStatement(pair.publicKey, 'workspace.group.create', payload, signature)).toBe(false);
+    await expect(signStatement(pair.privateKey, 'Workspace.Channel.Create', payload)).rejects.toThrow();
+  });
+
+  it('聊天/文件签名上下文与帧清单跨语言向量一致', async () => {
+    const event = vectors.content_event;
+    const manifest = await frameManifestHash(event.frame_digests.map((digest: string) => h(digest)));
+    expect(manifest).toEqual(h(event.manifest_hash));
+    expect(contentEventPayload({
+      spaceId: h(event.space_id), channelId: event.channel_id, username: event.username, deviceId: event.device_id,
+      eventId: h(event.event_id), eventKind: event.kind, domain: event.domain, epoch: event.epoch,
+      itemId: h(event.item_id), frameCount: event.frame_count, manifestHash: manifest, targetItemId: h(event.target_item_id),
+    })).toEqual(h(event.payload));
+  });
+});

packages/core/test/vectors.test.ts

@@ -182,30 +182,6 @@ describe('raw 帧', () => {
   });
 });
 
-describe('设备名', () => {
-  it('固定 IV 下的密文一致,并能解回', async () => {
-    const session = await openVectorSession();
-    for (const l of vectors.labels) {
-      const sealed = await session.sealLabel(l.name, { iv: h(l.iv) });
-      expect(toHex(sealed)).toBe(l.blob);
-      expect(sealed.length).toBeLessThanOrEqual(256);
-      expect(await session.openLabel(sealed, session.endpointHash)).toBe(l.name);
-    }
-  });
-
-  it('换一个终端的哈希就解不开(AAD 绑定终端)', async () => {
-    const session = await openVectorSession();
-    const sealed = await session.sealLabel('我的 iPhone');
-    await expect(session.openLabel(sealed, new Uint8Array(32))).rejects.toThrowError(IntegrityError);
-  });
-
-  it('超过 228 字节 UTF-8 时拒绝', async () => {
-    const session = await openVectorSession();
-    await expect(session.sealLabel('x'.repeat(229))).rejects.toThrow();
-    await expect(session.sealLabel('x'.repeat(228))).resolves.toHaveLength(256);
-  });
-});
-
 describe('链接', () => {
   it('合法链接解析结果与向量一致', () => {
     for (const v of vectors.links.valid) {

scripts/browser-account-channel-smoke.js

@@ -36,7 +36,7 @@ async (page) => {
     await owner.getByRole('button', { name: '新建空间', exact: true }).waitFor();
     if (await owner.getByLabel('个人名称', { exact: true }).inputValue() !== '多设备测试用户') throw new Error('Profile did not survive reload');
     await owner.getByRole('img', { name: '个人头像', exact: true }).waitFor();
-    results.push('login, encrypted profile and avatar survive reload');
+    results.push('server-owned profile and avatar survive login and reload');
     await owner.getByRole('button', { name: '新建空间', exact: true }).click();
     await owner.getByLabel('空间名称(加入者和服务端可见)').fill('架构验收空间');
     await owner.getByRole('button', { name: '创建', exact: true }).click();
@@ -52,9 +52,11 @@ async (page) => {
     await owner.getByRole('button', { name: '频道设置 常规', exact: true }).click();
     await owner.getByLabel('所属分组').selectOption({ label: '工作' });
     await owner.getByRole('button', { name: '保存', exact: true }).click();
+    await owner.getByRole('button', { name: '保存', exact: true }).waitFor({ state: 'hidden' });
     await owner.getByRole('button', { name: '重命名分组 工作', exact: true }).click();
     await owner.getByLabel('分组名称', { exact: true }).fill('项目');
     await owner.getByRole('button', { name: '保存', exact: true }).click();
+    await owner.getByRole('button', { name: '保存', exact: true }).waitFor({ state: 'hidden' });
     await owner.getByRole('button', { name: '分组 项目', exact: true }).click();
     if (await owner.getByRole('button', { name: '讨论', exact: true }).isVisible()) throw new Error('Group did not collapse');
     await owner.getByRole('button', { name: '分组 项目', exact: true }).click();
@@ -65,12 +67,14 @@ async (page) => {
     await owner.getByRole('button', { name: '频道设置 讨论', exact: true }).click();
     await owner.getByLabel('所属分组').selectOption({ label: '未分组' });
     await owner.getByRole('button', { name: '保存', exact: true }).click();
+    await owner.getByRole('button', { name: '保存', exact: true }).waitFor({ state: 'hidden' });
     if (await owner.getByRole('region', { name: '频道分组 项目', exact: true }).getByRole('button', { name: '讨论', exact: true }).count()) throw new Error('Ungrouping did not remove group membership');
     await owner.getByRole('button', { name: '频道设置 讨论', exact: true }).click();
     await owner.getByLabel('所属分组').selectOption({ label: '项目' });
     await owner.getByRole('button', { name: '保存', exact: true }).click();
+    await owner.getByRole('button', { name: '保存', exact: true }).waitFor({ state: 'hidden' });
     await owner.getByRole('button', { name: '常规', exact: true }).click();
-    results.push('channel groups create, rename, collapse and survive encrypted replay');
+    results.push('backend channels and groups create, rename, collapse and survive reload');
     const path = new URL(owner.url()).pathname;
     if (owner.url().includes('#')) throw new Error('Account channel navigation retained a secret fragment');
     await owner.locator('textarea').last().fill('常规 thread 聊天验证');
@@ -116,7 +120,7 @@ async (page) => {
     await owner.getByLabel('移动所选文件到文件夹').selectOption({ label: '资料目录' });
     await owner.getByRole('button', { name: '资料目录', exact: true }).dblclick();
     await owner.getByRole('button', { name: 'architecture-file.txt', exact: true }).waitFor();
-    results.push('folder navigation and encrypted file moves work');
+    results.push('backend folders and file locations update without re-encrypting content');
     await second.goto(origin);
     const selfRow = second.getByRole('region', { name: '账号设备' }).locator('div').filter({ has: second.getByText('本机', { exact: true }) });
     await selfRow.locator('input').fill('验收副设备');

scripts/browser-backend-data-smoke.js

@@ -0,0 +1,53 @@
+// Works against either the development proxy or the embedded production frontend.
+async (page) => {
+  const origin = new URL(page.url()).origin;
+  const context = await page.context().browser().newContext({ viewport: { width: 1440, height: 900 } });
+  const owner = await context.newPage(); const results = [];
+  try {
+    await owner.goto(origin);
+    await owner.getByLabel('用户名', { exact: true }).fill(`backend_${Date.now()}`);
+    await owner.getByLabel('密码', { exact: true }).fill('Backend-data-test-password');
+    await owner.getByRole('button', { name: '创建账号', exact: true }).click();
+    await owner.getByRole('button', { name: '新建空间', exact: true }).click();
+    await owner.getByLabel('空间名称(加入者和服务端可见)').fill('后端数据源测试');
+    await owner.getByRole('button', { name: '创建', exact: true }).click();
+    await owner.getByRole('button', { name: '常规', exact: true }).waitFor();
+    const spaceId = new URL(owner.url()).pathname.split('/').pop();
+    await owner.getByRole('button', { name: '新建频道分组', exact: true }).click();
+    await owner.getByLabel('分组名称', { exact: true }).fill('前端分组');
+    const requestPromise = owner.waitForRequest(request => request.method() === 'POST' && request.url().endsWith(`/spaces/${spaceId}/groups`));
+    await owner.getByRole('button', { name: '创建', exact: true }).click();
+    const request = await requestPromise;
+    const allHeaders = await request.allHeaders();
+    const headers = Object.fromEntries(['authorization', 'x-wd-role', 'x-wd-endpoint', 'x-wd-account', 'content-type'].filter(key => allHeaders[key]).map(key => [key, allHeaders[key]]));
+    await owner.getByRole('button', { name: '分组 前端分组', exact: true }).waitFor();
+    const initial = await context.request.get(`${origin}/api/v1/spaces/${spaceId}/structure`, { headers }).then(r => r.json());
+    const groupId = initial.structure.groups[0].id;
+    const renamed = await context.request.patch(`${origin}/api/v1/spaces/${spaceId}/groups/${groupId}`, { headers, data: { name: '后端分组' } });
+    if (!renamed.ok()) throw new Error(`Backend rename failed ${renamed.status()}`);
+    await owner.getByRole('button', { name: '分组 后端分组', exact: true }).waitFor();
+    const created = await context.request.post(`${origin}/api/v1/spaces/${spaceId}/channels`, { headers, data: { name: '后端频道', groupId } });
+    if (created.status() !== 201) throw new Error('Backend channel creation failed');
+    await owner.getByRole('button', { name: '后端频道', exact: true }).waitFor();
+    results.push('direct backend group and channel edits update the UI without client structure records');
+    const locationResponse = owner.waitForResponse(response => response.request().method() === 'PUT' && response.url().endsWith(`/spaces/${spaceId}/locations`));
+    await owner.getByRole('region', { name: '常规 聊天', exact: true }).locator('textarea').fill('后端作者归属测试');
+    await owner.getByRole('button', { name: '发送消息', exact: true }).click();
+    if (!(await locationResponse).ok()) throw new Error('Backend item association failed');
+    const profile = await context.request.patch(`${origin}/api/v1/accounts/profile`, { headers, data: { displayName: '后端昵称' } });
+    if (!profile.ok()) throw new Error('Backend profile update failed');
+    await owner.getByRole('article', { name: '后端昵称 的消息', exact: true }).getByText('后端作者归属测试', { exact: true }).waitFor();
+    results.push('backend account profile and stored authors determine message identity');
+    const spaces = await context.request.get(`${origin}/api/v1/accounts/spaces`, { headers }).then(r => r.json());
+    if (!spaces.some(space => space.id === spaceId) || spaces.some(space => 'read_hash' in space || 'ownerLink' in space || 'memberLink' in space)) throw new Error('Space metadata catalog is invalid');
+    for (const path of ['/accounts/profile/import', `/spaces/${spaceId}/structure/import`]) {
+      const response = await context.request.post(`${origin}/api/v1${path}`, { headers, data: {} });
+      if (response.status() !== 404 && response.status() !== 405) throw new Error('Unexpected legacy import route');
+    }
+    await owner.reload();
+    await owner.getByRole('button', { name: '后端频道', exact: true }).waitFor();
+    await owner.getByRole('article', { name: '后端昵称 的消息', exact: true }).waitFor();
+    results.push('server-owned state survives reload and there are no migration endpoints');
+    return { passed: results };
+  } finally { await context.close(); }
+}

scripts/browser-channel-domains-smoke.js

@@ -0,0 +1,50 @@
+async (page) => {
+  const origin = page.url().startsWith('http') ? new URL(page.url()).origin : 'http://127.0.0.1:5179'; const browser = page.context().browser(); const contexts = []; const results = [];
+  const password = 'Channel-domains-test-password'; const suffix = Date.now(); const ownerName = `domains_owner_${suffix}`; const memberName = `domains_member_${suffix}`;
+  let owner, member; const failures = [];
+  async function account(username) {
+    const context = await browser.newContext({ viewport: { width: 1440, height: 900 } }); contexts.push(context); const target = await context.newPage();
+    await target.goto(origin); await target.getByLabel('用户名', { exact: true }).fill(username); await target.getByLabel('密码', { exact: true }).fill(password);
+    await target.getByRole('button', { name: '创建账号', exact: true }).click(); await target.getByRole('button', { name: '新建空间', exact: true }).waitFor(); return target;
+  }
+  async function send(target, text) { await target.getByRole('region', { name: '常规 聊天', exact: true }).locator('textarea').fill(text); await target.getByRole('button', { name: '发送消息', exact: true }).click(); await target.getByRole('article').getByText(text, { exact: true }).waitFor(); }
+  try {
+    owner = await account(ownerName); member = await account(memberName);
+    member.on('response', async response => { if (response.status() >= 400 && response.url().includes('/api/v1/')) failures.push({ status: response.status(), method: response.request().method(), path: new URL(response.url()).pathname, code: (await response.json().catch(() => ({}))).error }); });
+    await owner.getByRole('button', { name: '新建空间', exact: true }).click(); await owner.getByLabel('空间名称(加入者和服务端可见)').fill('独立数据域测试'); await owner.getByRole('button', { name: '创建', exact: true }).click();
+    await owner.getByRole('button', { name: '常规', exact: true }).waitFor(); const path = new URL(owner.url()).pathname;
+    await send(owner, '加入前的历史聊天');
+    const ownerExplorer = owner.getByRole('region', { name: '频道文件管理器' });
+    await ownerExplorer.locator('input[type=file]').setInputFiles({ name: 'old-domain-file.txt', mimeType: 'text/plain', buffer: Buffer.from('historical file must remain private') });
+    await owner.getByRole('button', { name: '继续上传', exact: true }).click(); await owner.getByRole('button', { name: 'old-domain-file.txt', exact: true }).waitFor();
+    await owner.getByRole('button', { name: '在未分组新建频道', exact: true }).click(); await owner.getByLabel('频道名称', { exact: true }).fill('单独授权频道'); await owner.getByRole('button', { name: '创建频道', exact: true }).click();
+    await owner.getByRole('button', { name: '单独授权频道', exact: true }).waitFor(); await owner.getByRole('button', { name: '常规', exact: true }).click();
+    await owner.getByRole('button', { name: '频道设置 常规', exact: true }).click(); await owner.getByLabel('新成员可读历史聊天').uncheck(); await owner.getByLabel('新成员可读历史文件').uncheck();
+    await owner.getByRole('button', { name: '保存', exact: true }).click(); await owner.getByRole('button', { name: '保存', exact: true }).waitFor({ state: 'hidden' });
+    await owner.getByRole('button', { name: '空间设置', exact: true }).click(); await owner.getByLabel('被邀请用户的用户名').fill(memberName); await owner.getByRole('button', { name: '发送邀请', exact: true }).click();
+    await owner.getByText(`${memberName} · 已邀请`, { exact: true }).waitFor(); await owner.getByRole('dialog').getByRole('button', { name: '关闭', exact: true }).click();
+    await member.goto(origin + path); await member.getByRole('button', { name: '接受并加入空间', exact: true }).click(); await member.getByRole('button', { name: '常规', exact: true }).waitFor();
+    if (await member.getByRole('button', { name: '单独授权频道', exact: true }).count()) throw new Error('Member received an unauthorized channel');
+    if (await member.getByRole('article').getByText('加入前的历史聊天', { exact: true }).count()) throw new Error('Member received historical chat keys');
+    if (await member.getByRole('button', { name: 'old-domain-file.txt', exact: true }).count()) throw new Error('Member received historical file keys');
+    await send(owner, '加入后的新聊天'); await member.getByRole('article').getByText('加入后的新聊天', { exact: true }).waitFor();
+    const ownerMessage = owner.locator('article').filter({ hasText: '加入后的新聊天' });
+    const memberCopy = member.locator('article').filter({ hasText: '加入后的新聊天' });
+    if (await ownerMessage.evaluate(element => getComputedStyle(element).flexDirection) !== 'row-reverse'
+        || await memberCopy.evaluate(element => getComputedStyle(element).flexDirection) !== 'row') throw new Error('Messages are not aligned by sender');
+    await send(member, '成员发言验证'); await owner.getByRole('article').getByText('成员发言验证', { exact: true }).waitFor();
+    results.push('default-channel access is automatic; other channels and past epochs remain inaccessible');
+    const explorer = ownerExplorer;
+    await explorer.locator('input[type=file]').setInputFiles({ name: 'new-domain-file.txt', mimeType: 'text/plain', buffer: Buffer.from('independent random file key verification') });
+    await owner.getByRole('button', { name: '继续上传', exact: true }).click(); await member.getByRole('button', { name: 'new-domain-file.txt', exact: true }).waitFor();
+    await member.getByRole('button', { name: 'new-domain-file.txt', exact: true }).dblclick();
+    await member.getByRole('dialog').locator('pre').filter({ hasText: 'independent random file key verification' }).waitFor();
+    results.push('file-group key unwraps an independent file key and decrypts the file on another account');
+    await member.getByRole('dialog').getByRole('button', { name: '关闭', exact: true }).click(); await member.reload(); await member.getByRole('article').getByText('加入后的新聊天', { exact: true }).waitFor();
+    if (await member.getByRole('article').getByText('加入前的历史聊天', { exact: true }).count()) throw new Error('Reload restored disallowed history');
+    results.push('authorization and epoch boundaries survive reload');
+    return { passed: results };
+  } catch (error) {
+    throw new Error(`${error.message}; failures=${JSON.stringify(failures)}; owner alerts=${JSON.stringify(owner ? await owner.getByRole('alert').allTextContents() : [])}; member alerts=${JSON.stringify(member ? await member.getByRole('alert').allTextContents() : [])}`);
+  } finally { for (const context of contexts) await context.close(); }
+}

scripts/browser-chat-files-smoke.js

@@ -42,13 +42,20 @@ async (page) => {
     await file.getByRole('img', { name: '小白 的头像', exact: true }).waitFor();
     await viewer.reload(); await viewer.getByRole('article', { name: '小白 上传了 project-notes.txt', exact: true }).getByRole('img', { name: '小白 的头像', exact: true }).waitFor();
     if (downloads !== 1) throw new Error('Reloading file bubbles consumed a download');
-    results.push('identity survives download updates and encrypted history replay without automatic content reads');
+    results.push('server-owned identity survives download updates and reload without automatic content reads');
     await viewer.getByRole('region', { name: '常规 聊天', exact: true }).locator('textarea').fill('我收到了。'); await viewer.getByRole('button', { name: '发送消息', exact: true }).click();
     await sender.getByRole('article', { name: '小黑 的消息', exact: true }).getByText('我收到了。', { exact: true }).waitFor();
     results.push('each participant keeps their own sender identity');
     await viewer.screenshot({ path: 'C:/Users/JustMe/Desktop/webdrop-proj/.playwright-mcp/chat-file-messages.png', fullPage: true });
     for (const width of [1440, 390]) { await viewer.setViewportSize({ width, height: 900 }); for (const colorScheme of ['light', 'dark']) {
-      await viewer.emulateMedia({ colorScheme }); if (await viewer.evaluate(() => document.documentElement.scrollWidth > innerWidth)) throw new Error('Chat layout overflow');
+      await viewer.emulateMedia({ colorScheme });
+      // Allow the media-query subscription to switch the React workspace layout.
+      await viewer.evaluate(() => new Promise(resolve => requestAnimationFrame(() => requestAnimationFrame(resolve))));
+      if (await viewer.evaluate(() => document.documentElement.scrollWidth > innerWidth)) {
+        const overflow = await viewer.evaluate(() => ({ width: innerWidth, scroll: document.documentElement.scrollWidth,
+          elements: [...document.querySelectorAll('body *')].filter(e => e.getBoundingClientRect().right > innerWidth + 1).slice(0, 12).map(e => ({ tag: e.tagName, cls: e.className, right: e.getBoundingClientRect().right })) }));
+        throw new Error(`Chat layout overflow: ${JSON.stringify(overflow)}`);
+      }
     } }
     return { passed: results };
   } finally { for (const context of contexts) await context.close(); }

scripts/browser-passkey-smoke.js

@@ -0,0 +1,44 @@
+async (page) => {
+  const origin = new URL(page.url()).origin;
+  const context = await page.context().browser().newContext(); const owner = await context.newPage();
+  const cdp = await context.newCDPSession(owner); const results = [];
+  const username = `passkey_${Date.now()}`; const password = 'Passkey-test-password-2026';
+  const errors = []; const calls = [];
+  owner.on('pageerror', error => errors.push(error.message));
+  owner.on('request', request => { if (request.url().includes('/api/v1/')) calls.push(new URL(request.url()).pathname); });
+  await cdp.send('WebAuthn.enable');
+  const { authenticatorId } = await cdp.send('WebAuthn.addVirtualAuthenticator', { options: { protocol: 'ctap2', ctap2Version: 'ctap2_1', transport: 'internal', hasResidentKey: true,
+    hasUserVerification: true, isUserVerified: true, automaticPresenceSimulation: true, hasPrf: true } });
+  let secretExtensionSent = false;
+  owner.on('request', request => { if (request.url().includes('/accounts/passkeys/') && request.postData()) {
+    const body = JSON.parse(request.postData()); if (body.credential && JSON.parse(body.credential).clientExtensionResults?.prf?.results) secretExtensionSent = true;
+  } });
+  try {
+    await owner.goto(origin); await owner.getByLabel('用户名', { exact: true }).fill(username); await owner.getByLabel('密码', { exact: true }).fill(password);
+    await owner.getByRole('button', { name: '创建账号', exact: true }).click(); await owner.getByRole('button', { name: '新建空间', exact: true }).waitFor();
+    await owner.getByLabel('Passkey名称', { exact: true }).fill('测试恢复凭据'); await owner.getByLabel('验证账号密码', { exact: true }).fill(password);
+    await owner.getByRole('button', { name: '绑定Passkey', exact: true }).click();
+    await owner.getByText('测试恢复凭据 · 登录与解密恢复', { exact: true }).waitFor();
+    if (secretExtensionSent) throw new Error('PRF results were sent to the API');
+    results.push('verified WebAuthn binding enables encrypted recovery without sending PRF outputs to the server');
+    await owner.getByRole('button', { name: '新建空间', exact: true }).click(); await owner.getByLabel('空间名称(加入者和服务端可见)').fill('Passkey恢复测试');
+    await owner.getByRole('button', { name: '创建', exact: true }).click(); await owner.getByRole('button', { name: '常规', exact: true }).waitFor();
+    await owner.getByRole('region', { name: '常规 聊天', exact: true }).locator('textarea').fill('Passkey恢复后的私密内容'); await owner.getByRole('button', { name: '发送消息', exact: true }).click();
+    await owner.getByRole('article').getByText('Passkey恢复后的私密内容', { exact: true }).waitFor();
+    const path = new URL(owner.url()).pathname;
+    await owner.goto(origin); await owner.getByRole('button', { name: '退出登录', exact: true }).click();
+    await owner.getByRole('button', { name: '使用Passkey登录', exact: true }).waitFor(); await owner.getByRole('button', { name: '使用Passkey登录', exact: true }).click();
+    await owner.getByRole('button', { name: '新建空间', exact: true }).waitFor(); await owner.goto(origin + path);
+    await owner.getByRole('article').getByText('Passkey恢复后的私密内容', { exact: true }).waitFor();
+    results.push('Passkey restores the vault and decrypts resources without entering the password');
+    await owner.goto(origin); await owner.getByRole('button', { name: '撤销 测试恢复凭据', exact: true }).click(); await owner.getByText('Passkey已撤销', { exact: true }).waitFor();
+    await owner.getByRole('button', { name: '退出登录', exact: true }).click();
+    await owner.getByLabel('用户名', { exact: true }).fill(username); await owner.getByLabel('密码', { exact: true }).fill(password);
+    await owner.getByRole('button', { name: '登录并同步', exact: true }).click(); await owner.getByRole('button', { name: '新建空间', exact: true }).waitFor();
+    results.push('revocation removes the credential while password recovery remains available');
+    return { passed: results };
+  } catch (error) {
+    const inputs = await owner.locator('input').evaluateAll(inputs => inputs.map(input => ({ name: input.name, type: input.type, length: input.value.length, valid: input.validity.valid, message: input.validationMessage })));
+    throw new Error(`Passkey smoke failed after ${results.length} checks: ${error.message}; body=${(await owner.locator('body').innerText()).slice(0, 800)}; inputs=${JSON.stringify(inputs)}; errors=${JSON.stringify(errors)}; calls=${JSON.stringify(calls)}`);
+  } finally { await cdp.send('WebAuthn.removeVirtualAuthenticator', { authenticatorId }).catch(() => {}); await context.close(); }
+}

scripts/check-api-contract.mjs

@@ -1,4 +1,5 @@
 import { readFileSync } from 'node:fs';
+import { createHash } from 'node:crypto';
 
 const read = (path) => readFileSync(new URL(`../${path}`, import.meta.url), 'utf8');
 const semver = /^(0|[1-9]\d*)\.(0|[1-9]\d*)\.(0|[1-9]\d*)(?:-([0-9A-Za-z-]+(?:\.[0-9A-Za-z-]+)*))?(?:\+[0-9A-Za-z-]+(?:\.[0-9A-Za-z-]+)*)?$/;
@@ -8,6 +9,12 @@ const fail = (message) => {
   process.exit(1);
 };
 
+const dtoSources = ['server/src/WebDrop.Api/Json/ApiJson.cs', 'server/src/WebDrop.Core/Channels/Dtos.cs', 'server/src/WebDrop.Core/Channels/Settings.cs', 'server/src/WebDrop.Core/Common/Enums.cs', 'server/src/WebDrop.Core/Spaces/Workspace.cs', 'server/src/WebDrop.Core/Accounts/AccountProfile.cs', 'server/src/WebDrop.Api/Passkeys/PasskeyDtos.cs', 'server/src/WebDrop.Core/Spaces/WorkspaceCrypto.cs', 'server/src/WebDrop.Api/Endpoints/Endpoints.WorkspaceCrypto.cs'];
+const dtoDigest = createHash('sha256').update(dtoSources.map(path => `${path}\n${read(path).replace(/\r\n/g, '\n')}\n`).join('')).digest('hex');
+const generatedDigest = /backend-contract-sha256: ([a-f0-9]{64})/.exec(read('web/src/api/generated.ts'))?.[1];
+if (generatedDigest !== dtoDigest) fail('Backend DTOs changed. Regenerate with dotnet run --project tools/ContractGenerator -- .');
+if (JSON.parse(read('contracts/api.schemas.json'))['x-backend-contract-sha256'] !== dtoDigest) fail('Generated API schemas are stale. Run ContractGenerator.');
+
 if (typeof contract.version !== 'string' || !semver.test(contract.version)) {
   fail('contracts/api-contract.json must contain a SemVer version.');
 }
@@ -17,14 +24,14 @@ const openapi = read('docs/openapi.yaml');
 const openapiVersion = /^info:\s*\r?\n(?:.*\r?\n)*?\s+version:\s*([^\s#]+)/m.exec(openapi)?.[1];
 if (openapiVersion !== contract.version) fail(`OpenAPI version ${openapiVersion ?? '(missing)'} differs from ${contract.version}.`);
 
-const backend = read('server/src/WebDrop.Api/ApiContract.cs');
+const backend = read('server/src/WebDrop.Api/Hosting/ApiContract.cs');
 const backendVersion = /const string Version = "([^"]+)"/.exec(backend)?.[1];
 if (backendVersion !== contract.version) fail(`backend version ${backendVersion ?? '(missing)'} differs from ${contract.version}.`);
 
-const frontend = read('web/src/core-bridge/contract.ts');
+const frontend = read('web/src/api/contract.ts');
 const supportedMajor = Number(/SUPPORTED_API_CONTRACT_MAJOR\s*=\s*(\d+)/.exec(frontend)?.[1]);
 if (supportedMajor !== apiMajor) {
-  fail(`backend contract is ${contract.version}; frontend still supports API major ${supportedMajor || '(missing)'}. Update web/src/core-bridge/contract.ts.`);
+  fail(`backend contract is ${contract.version}; frontend still supports API major ${supportedMajor || '(missing)'}. Update web/src/api/contract.ts.`);
 }
 
 const tag = process.argv[2];

scripts/ci-publish-image.sh

@@ -0,0 +1,32 @@
+#!/usr/bin/env bash
+# 构建并推送一个镜像到 registry。开发镜像和发布镜像、主后端和文件服务都用它,构建和推送的细节只写在这里。
+# 用法: ci-publish-image.sh <镜像名> <Containerfile> <版本标签> [额外标签...]
+#   例: ci-publish-image.sh webdrop-api server/Containerfile dev-abc1234 dev
+# 需要环境变量: ZOT_REGISTRY、ZOT_USERNAME、ZOT_SECRET(Woodpecker 的密钥)
+set -euo pipefail
+
+name="$1"; containerfile="$2"; version="$3"; shift 3
+: "${ZOT_REGISTRY:?}" "${ZOT_USERNAME:?}" "${ZOT_SECRET:?}"
+: "${WOODPECKER_BACKEND_LOCAL_TEMP_DIR:=$HOME/woodpecker/work}"
+
+# 每个镜像一个构建缓存目录,两个镜像并行构建时互不干扰
+store="$(dirname "$WOODPECKER_BACKEND_LOCAL_TEMP_DIR")/buildah-cache/$name"
+mkdir -p "$store/storage" "$store/run"
+buildah() { command buildah --root "$store/storage" --runroot "$store/run" "$@"; }
+
+printf '%s' "$ZOT_SECRET" | buildah login --tls-verify=true --username "$ZOT_USERNAME" --password-stdin "$ZOT_REGISTRY"
+trap 'buildah logout "$ZOT_REGISTRY" >/dev/null 2>&1 || true' EXIT
+
+commit="${CI_COMMIT_SHA:-$(git rev-parse HEAD)}"
+image="$ZOT_REGISTRY/justme/$name:$version"
+buildah bud --layers --network host --format oci --platform linux/amd64 \
+  --build-arg "WEBDROP_FRONTEND_COMMIT=$commit" --build-arg "WEBDROP_FRONTEND_TAG=$version" \
+  --build-arg "WEBDROP_BACKEND_COMMIT=$commit" --build-arg "WEBDROP_BACKEND_TAG=$version" \
+  --build-arg "WEBDROP_BUILD_TIME=$(date -u +%Y-%m-%dT%H:%M:%SZ)" \
+  --tag "$image" --file "$containerfile" .
+
+buildah push "$image" "docker://$image"
+for extra in "$@"; do
+  buildah tag "$image" "$ZOT_REGISTRY/justme/$name:$extra"
+  buildah push "$ZOT_REGISTRY/justme/$name:$extra" "docker://$ZOT_REGISTRY/justme/$name:$extra"
+done

server/Containerfile

@@ -22,8 +22,10 @@ WORKDIR /src
 COPY server/Directory.Build.props ./server/
 COPY server/src/WebDrop.Api/WebDrop.Api.csproj ./server/src/WebDrop.Api/
 COPY server/src/WebDrop.Core/WebDrop.Core.csproj ./server/src/WebDrop.Core/
+COPY server/src/WebDrop.FileProtocol/WebDrop.FileProtocol.csproj ./server/src/WebDrop.FileProtocol/
 COPY server/src/WebDrop.Frontend/WebDrop.Frontend.csproj ./server/src/WebDrop.Frontend/
 COPY server/src/WebDrop.Storage/WebDrop.Storage.csproj ./server/src/WebDrop.Storage/
+COPY server/src/WebDrop.Sync/WebDrop.Sync.csproj ./server/src/WebDrop.Sync/
 RUN dotnet restore server/src/WebDrop.Api/WebDrop.Api.csproj \
     --runtime linux-x64
 COPY server/ ./server/

server/Containerfile.files

@@ -0,0 +1,37 @@
+# 文件服务(fileAPI):单独部署,放在存储所在的机器(例如家里的 NAS)。只依赖 FileProtocol 和 Sync,不带前端和数据库
+FROM mcr.microsoft.com/dotnet/sdk:10.0-noble-aot AS build
+WORKDIR /src
+COPY server/Directory.Build.props ./server/
+COPY server/src/WebDrop.FileApi/WebDrop.FileApi.csproj ./server/src/WebDrop.FileApi/
+COPY server/src/WebDrop.FileProtocol/WebDrop.FileProtocol.csproj ./server/src/WebDrop.FileProtocol/
+COPY server/src/WebDrop.Sync/WebDrop.Sync.csproj ./server/src/WebDrop.Sync/
+RUN dotnet restore server/src/WebDrop.FileApi/WebDrop.FileApi.csproj \
+    --runtime linux-x64
+COPY server/src/WebDrop.FileApi/ ./server/src/WebDrop.FileApi/
+COPY server/src/WebDrop.FileProtocol/ ./server/src/WebDrop.FileProtocol/
+COPY server/src/WebDrop.Sync/ ./server/src/WebDrop.Sync/
+RUN dotnet publish server/src/WebDrop.FileApi/WebDrop.FileApi.csproj \
+    --configuration Release \
+    --runtime linux-x64 \
+    --self-contained true \
+    --no-restore \
+    --output /out
+
+FROM mcr.microsoft.com/dotnet/runtime-deps:10.0 AS runtime
+ARG WEBDROP_BACKEND_COMMIT=unknown
+ARG WEBDROP_BACKEND_TAG=unknown
+ARG WEBDROP_BUILD_TIME=unknown
+LABEL org.opencontainers.image.revision=$WEBDROP_BACKEND_COMMIT \
+      org.opencontainers.image.version=$WEBDROP_BACKEND_TAG \
+      org.opencontainers.image.created=$WEBDROP_BUILD_TIME
+WORKDIR /app
+COPY --from=build /out/webdrop-files /app/webdrop-files
+RUN mkdir -p /data \
+    && chown 10001:10001 /data \
+    && chmod 0750 /data
+ENV ASPNETCORE_URLS=http://+:5100 \
+    FileApi__DataDir=/data \
+    DOTNET_EnableDiagnostics=0
+USER 10001:10001
+EXPOSE 5100
+ENTRYPOINT ["/app/webdrop-files"]

server/README.md

@@ -42,7 +42,7 @@ python3 scripts/smoke.py out/linux-x64/webdrop         # 跨平台版本,只用
 | `Captcha:ApiEndpoint` | 空 | 浏览器里 Cap widget 连接的地址,形如 `https://cap.example.com/<site_key>/`,经 `/info` 下发 |
 | `Captcha:SiteverifyUrl` | 空 | 本服务调用 Cap 校验 token 的地址,形如 `https://cap.example.com/<site_key>/siteverify`,可以是内网地址 |
 | `Captcha:Secret` | 空 | Cap 站点密钥的 secret,只在服务端使用 |
-| `Limits:*` | 见 `ServerLimits` | 负载、帧数、频道字节数、席位、TTL 上限等 |
+| `Limits:*` | 见 `ServerLimits` | 负载、帧数、频道字节数、成员人数上限、TTL 上限等 |
 
 ## 约束
 

server/WebDrop.slnx

@@ -1,9 +1,19 @@
 <Solution>
-  <Folder Name="/src/">
+  <!-- 主后端(hostAPI):账号、空间、频道、聊天、实时推送,以及内嵌的前端 -->
+  <Folder Name="/src/host/">
     <Project Path="src/WebDrop.Api/WebDrop.Api.csproj" />
-    <Project Path="src/WebDrop.Core/WebDrop.Core.csproj" />
     <Project Path="src/WebDrop.Frontend/WebDrop.Frontend.csproj" />
+  </Folder>
+  <!-- 文件服务(fileAPI):另一个进程,只保存超过阈值的大文件 -->
+  <Folder Name="/src/files/">
+    <Project Path="src/WebDrop.FileApi/WebDrop.FileApi.csproj" />
+    <Project Path="src/WebDrop.FileProtocol/WebDrop.FileProtocol.csproj" />
+  </Folder>
+  <!-- 两边共用:业务规则、数据库、S3 备份 -->
+  <Folder Name="/src/shared/">
+    <Project Path="src/WebDrop.Core/WebDrop.Core.csproj" />
     <Project Path="src/WebDrop.Storage/WebDrop.Storage.csproj" />
+    <Project Path="src/WebDrop.Sync/WebDrop.Sync.csproj" />
   </Folder>
   <Folder Name="/tests/">
     <Project Path="tests/WebDrop.Api.Tests/WebDrop.Api.Tests.csproj" />

server/scripts/smoke.ps1

@@ -46,12 +46,12 @@ try {
     $ownerH = Headers 'owner' $ownerTok $ownerSecret
 
     $created = Invoke-RestMethod "$base/api/v1/channels" -Method Post -Body $body -ContentType 'application/json' -Headers $ownerH
-    Check ($created.id -eq (B64 $id) -and $created.seats_used -eq 1) '创建频道成功'
+    Check ($created.id -eq (B64 $id) -and $created.members_used -eq 1) '创建频道成功'
     $cid = B64 $id
 
     $memberH = Headers 'write' $writeTok $memberSecret
-    $joined = Invoke-RestMethod "$base/api/v1/channels/$cid/seats" -Method Post -Headers $memberH
-    Check ($joined.seats_used -eq 2) '成员加入'
+    $joined = Invoke-RestMethod "$base/api/v1/channels/$cid/join" -Method Post -Headers $memberH
+    Check ($joined.members_used -eq 2) '成员加入'
 
     # enc 帧:负载 = 1024 档位 + 16 标签
     $item = Rand 16

server/scripts/smoke.py

@@ -71,8 +71,8 @@ try:
     check(status == 201, "创建频道")
     ch = b64(cid)
 
-    status, body = call("POST", f"/api/v1/channels/{ch}/seats", member_h)
-    check(status == 200 and json.loads(body)["seats_used"] == 2, "成员加入")
+    status, body = call("POST", f"/api/v1/channels/{ch}/join", member_h)
+    check(status == 200 and json.loads(body)["members_used"] == 2, "成员加入")
 
     item = os.urandom(16)
     f = frame(item, 0, 9, 1040, 0x42)

server/src/WebDrop.Api/ApiContract.cs

@@ -1,7 +0,0 @@
-namespace WebDrop.Api;
-
-public static class ApiContract
-{
-    // Keep this aligned with contracts/api-contract.json and docs/openapi.yaml.
-    public const string Version = "2.1.0";
-}

server/src/WebDrop.Api/ApiJson.cs

@@ -1,156 +0,0 @@
-using System.Text.Json.Serialization;
-using WebDrop.Core;
-
-namespace WebDrop.Api;
-
-public sealed class ErrorBody
-{
-    [JsonPropertyName("error")] public required string Error { get; init; }
-}
-
-public sealed class GoneLogBody
-{
-    [JsonPropertyName("error")] public string Error { get; init; } = "gone";
-    [JsonPropertyName("oldest_seq")] public required long OldestSeq { get; init; }
-}
-
-public sealed class ServerInfoBody
-{
-    [JsonPropertyName("protocol")] public int Protocol { get; init; } = 1;
-    [JsonPropertyName("contract_version")] public string ContractVersion { get; init; } = ApiContract.Version;
-    [JsonPropertyName("captcha")] public required CaptchaBody Captcha { get; init; }
-    [JsonPropertyName("transports")] public required TransportsBody Transports { get; init; }
-    [JsonPropertyName("limits")] public required LimitsBody Limits { get; init; }
-}
-
-/// <summary>告诉前端要不要出示验证码、widget 该连哪里(Cap 的 data-cap-api-endpoint)。</summary>
-public sealed class CaptchaBody
-{
-    [JsonPropertyName("provider")] public required string Provider { get; init; }
-    [JsonPropertyName("enabled")] public required bool Enabled { get; init; }
-    [JsonPropertyName("api_endpoint")] public string? ApiEndpoint { get; init; }
-}
-
-public sealed class TransportsBody
-{
-    [JsonPropertyName("websocket")] public bool WebSocket { get; init; } = true;
-    [JsonPropertyName("sse")] public bool Sse { get; init; } = true;
-    [JsonPropertyName("http3")] public required bool Http3 { get; init; }
-}
-
-public sealed class LimitsBody
-{
-    [JsonPropertyName("max_payload_bytes")] public required int MaxPayloadBytes { get; init; }
-    [JsonPropertyName("max_frames_per_item")] public required int MaxFramesPerItem { get; init; }
-    [JsonPropertyName("max_channel_bytes")] public required long MaxChannelBytes { get; init; }
-    [JsonPropertyName("max_seats")] public required int MaxSeats { get; init; }
-    [JsonPropertyName("max_ttl_seconds")] public required int MaxTtlSeconds { get; init; }
-}
-
-public sealed class AccountRegisterRequest
-{
-    [JsonPropertyName("public_key")] public required string PublicKey { get; init; }
-    [JsonPropertyName("username")] public required string Username { get; init; }
-    [JsonPropertyName("salt")] public required string Salt { get; init; }
-    [JsonPropertyName("verifier")] public required string Verifier { get; init; }
-    [JsonPropertyName("vault")] public required string Vault { get; init; }
-}
-public sealed class AccountSaltRequest { [JsonPropertyName("username")] public required string Username { get; init; } }
-public sealed class AccountSessionRequest
-{
-    [JsonPropertyName("device_id")] public string? DeviceId { get; init; }
-    [JsonPropertyName("device_name")] public string? DeviceName { get; init; }
-    [JsonPropertyName("username")] public required string Username { get; init; }
-    [JsonPropertyName("verifier")] public required string Verifier { get; init; }
-}
-public sealed class AccountVaultRequest
-{
-    [JsonPropertyName("revision")] public required long Revision { get; init; }
-    [JsonPropertyName("vault")] public required string Vault { get; init; }
-}
-public sealed class AccountSaltBody
-{
-    [JsonPropertyName("salt")] public required string Salt { get; init; }
-}
-public sealed class AccountSessionBody
-{
-    [JsonPropertyName("token")] public required string Token { get; init; }
-    [JsonPropertyName("username")] public required string Username { get; init; }
-}
-public sealed class AccountVaultBody
-{
-    [JsonPropertyName("revision")] public required long Revision { get; init; }
-    [JsonPropertyName("vault")] public required string Vault { get; init; }
-}
-
-public sealed class PublicKeyBody { [JsonPropertyName("public_key")] public required string PublicKey { get; init; } }
-public sealed class InvitationRequest
-{
-    [JsonPropertyName("username")] public required string Username { get; init; }
-    [JsonPropertyName("payload")] public required string Payload { get; init; }
-}
-public sealed class InvitationBody
-{
-    [JsonPropertyName("channel_id")] public required string ChannelId { get; init; }
-    [JsonPropertyName("username")] public required string Username { get; init; }
-    [JsonPropertyName("payload")] public required string Payload { get; init; }
-    [JsonPropertyName("created_at")] public required long CreatedAt { get; init; }
-}
-public sealed class JoinRequest { [JsonPropertyName("password")] public string? Password { get; init; } }
-public sealed class KeyPackageRequest { [JsonPropertyName("payload")] public required string Payload { get; init; } }
-public sealed class AccountDeviceNameRequest { [JsonPropertyName("name")] public required string Name { get; init; } }
-public sealed class AccountDeviceBody
-{
-    [JsonPropertyName("id")] public required string Id { get; init; }
-    [JsonPropertyName("name")] public required string Name { get; init; }
-    [JsonPropertyName("created_at")] public required long CreatedAt { get; init; }
-    [JsonPropertyName("last_seen")] public required long LastSeen { get; init; }
-    [JsonPropertyName("current")] public required bool Current { get; init; }
-}
-public sealed class AccountChannelBody
-{
-    [JsonPropertyName("channel_id")] public required string ChannelId { get; init; }
-    [JsonPropertyName("role")] public required string Role { get; init; }
-    [JsonPropertyName("payload")] public required string Payload { get; init; }
-    [JsonPropertyName("created_at")] public required long CreatedAt { get; init; }
-}
-public sealed class MemberBody
-{
-    [JsonPropertyName("username")] public required string Username { get; init; }
-    [JsonPropertyName("role")] public required string Role { get; init; }
-    [JsonPropertyName("joined_at")] public required long JoinedAt { get; init; }
-}
-
-[JsonSerializable(typeof(ErrorBody))]
-[JsonSerializable(typeof(GoneLogBody))]
-[JsonSerializable(typeof(ServerInfoBody))]
-[JsonSerializable(typeof(ChannelInfo))]
-[JsonSerializable(typeof(ShareInfo))]
-[JsonSerializable(typeof(CreateShareRequest))]
-[JsonSerializable(typeof(ShareSettingsPatch))]
-[JsonSerializable(typeof(FinishShareRequest))]
-[JsonSerializable(typeof(CreateChannelRequest))]
-[JsonSerializable(typeof(ChannelSettingsPatch))]
-[JsonSerializable(typeof(SeatJoined))]
-[JsonSerializable(typeof(List<SeatInfo>))]
-[JsonSerializable(typeof(AppendResult))]
-[JsonSerializable(typeof(SiteverifyRequest))]
-[JsonSerializable(typeof(SiteverifyResponse))]
-[JsonSerializable(typeof(AccountRegisterRequest))]
-[JsonSerializable(typeof(AccountSaltRequest))]
-[JsonSerializable(typeof(AccountSessionRequest))]
-[JsonSerializable(typeof(AccountVaultRequest))]
-[JsonSerializable(typeof(AccountSaltBody))]
-[JsonSerializable(typeof(AccountSessionBody))]
-[JsonSerializable(typeof(AccountVaultBody))]
-[JsonSerializable(typeof(PublicKeyBody))]
-[JsonSerializable(typeof(InvitationRequest))]
-[JsonSerializable(typeof(List<InvitationBody>))]
-[JsonSerializable(typeof(JoinRequest))]
-[JsonSerializable(typeof(List<MemberBody>))]
-[JsonSerializable(typeof(KeyPackageRequest))]
-[JsonSerializable(typeof(List<AccountChannelBody>))]
-[JsonSerializable(typeof(AccountDeviceNameRequest))]
-[JsonSerializable(typeof(List<AccountDeviceBody>))]
-[JsonSourceGenerationOptions(DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull)]
-public sealed partial class ApiJson : JsonSerializerContext;

server/src/WebDrop.Api/ChannelHub.cs

@@ -1,104 +0,0 @@
-using WebDrop.Core;
-
-namespace WebDrop.Api;
-
-/// <summary>
-/// 进程内的订阅枢纽。只传递「有变化」的信号,订阅者被唤醒后自己从日志里按游标读取,
-/// 所以不存在回放与实时之间漏帧的竞态,也不需要为慢客户端缓冲数据。
-/// 因此只支持单实例部署(见 architecture.md)。
-/// </summary>
-public sealed class ChannelHub : IChannelEvents
-{
-    private readonly object _gate = new();
-    private readonly Dictionary<Id16, Signal> _signals = [];
-
-    public Subscription Subscribe(Id16 id)
-    {
-        lock (_gate)
-        {
-            if (!_signals.TryGetValue(id, out var signal)) _signals[id] = signal = new Signal();
-            signal.Refs++;
-            return new Subscription(this, id, signal);
-        }
-    }
-
-    public void Advanced(Id16 channelId, long seq) => Publish(channelId, s => s.Seq = Math.Max(s.Seq, seq));
-    public void SettingsChanged(Id16 channelId) => Publish(channelId, s => s.SettingsVersion++);
-    public void SeatsChanged(Id16 channelId) => Publish(channelId, s => s.SeatsVersion++);
-    public void ChannelDeleted(Id16 channelId) => Publish(channelId, s => s.Deleted = true);
-
-    private void Publish(Id16 id, Action<Signal> mutate)
-    {
-        TaskCompletionSource? toComplete;
-        lock (_gate)
-        {
-            if (!_signals.TryGetValue(id, out var signal)) return; // 没有订阅者,无需通知
-            mutate(signal);
-            toComplete = signal.Replace();
-        }
-        toComplete.TrySetResult(); // 在锁外完成,避免续体在锁内运行
-    }
-
-    private void Release(Id16 id, Signal signal)
-    {
-        lock (_gate)
-        {
-            if (--signal.Refs == 0) _signals.Remove(id);
-        }
-    }
-
-    internal sealed class Signal
-    {
-        private TaskCompletionSource _tcs = New();
-        public int Refs;
-        public long Seq;
-        public int SettingsVersion;
-        public int SeatsVersion;
-        public bool Deleted;
-
-        public Task Changed => _tcs.Task;
-
-        public TaskCompletionSource Replace()
-        {
-            var old = _tcs;
-            _tcs = New();
-            return old;
-        }
-
-        private static TaskCompletionSource New() => new(TaskCreationOptions.RunContinuationsAsynchronously);
-    }
-
-    /// <summary>
-    /// 用法:先取 <see cref="Changed"/>,再读状态,最后等待取到的那个任务。
-    /// 取任务之后发生的任何发布都会让它完成,不会丢通知。
-    /// </summary>
-    public sealed class Subscription : IDisposable
-    {
-        private readonly ChannelHub _hub;
-        private readonly Id16 _id;
-        private readonly Signal _signal;
-        private int _disposed;
-
-        internal Subscription(ChannelHub hub, Id16 id, Signal signal)
-        {
-            _hub = hub;
-            _id = id;
-            _signal = signal;
-        }
-
-        public Task Changed
-        {
-            get { lock (_hub._gate) return _signal.Changed; }
-        }
-
-        public (int Settings, int Seats, bool Deleted) State
-        {
-            get { lock (_hub._gate) return (_signal.SettingsVersion, _signal.SeatsVersion, _signal.Deleted); }
-        }
-
-        public void Dispose()
-        {
-            if (Interlocked.Exchange(ref _disposed, 1) == 0) _hub.Release(_id, _signal);
-        }
-    }
-}

server/src/WebDrop.Api/Endpoints.ChannelAccess.cs

@@ -1,54 +0,0 @@
-using WebDrop.Core;
-using WebDrop.Storage;
-
-namespace WebDrop.Api;
-
-public static partial class Endpoints
-{
-    private static void MapChannelAccess(RouteGroupBuilder api, SqliteAccountStore accounts)
-    {
-        api.MapGet("/accounts/channels", (HttpContext ctx, ChannelService svc) =>
-        {
-            if (!TryAccount(ctx, accounts, out var username)) throw new WebDropException(ErrorCode.AccountRequired);
-            var packages = svc.AccountChannels(username).Select(k => new AccountChannelBody
-            {
-                ChannelId = k.ChannelId.ToBase64Url(), Role = k.Role, Payload = k.Payload, CreatedAt = k.CreatedAt,
-            }).ToList();
-            return Json(packages, ApiJson.Default.ListAccountChannelBody);
-        });
-        api.MapPut("/channels/{id}/key-package", async (string id, HttpContext ctx, ChannelService svc, CancellationToken ct) =>
-        {
-            var req = await ReadJson(ctx.Request, ApiJson.Default.KeyPackageRequest, ct);
-            svc.SaveOwnerKeyPackage(ParseId(id), RequestAuth.FromHeaders(ctx.Request, false), req.Payload);
-            return Results.NoContent();
-        });
-        api.MapGet("/accounts/users/{username}/key", (string username, HttpContext ctx) =>
-        {
-            if (!TryAccount(ctx, accounts, out _)) throw new WebDropException(ErrorCode.AccountRequired);
-            var key = accounts.GetPublicKey(NormalizeUsername(username));
-            if (key is null) throw new WebDropException(ErrorCode.NotFound);
-            return Json(new PublicKeyBody { PublicKey = key }, ApiJson.Default.PublicKeyBody);
-        });
-        api.MapGet("/accounts/invitations", (HttpContext ctx, ChannelService svc) =>
-        {
-            if (!TryAccount(ctx, accounts, out var username)) throw new WebDropException(ErrorCode.AccountRequired);
-            return Json(InvitationBodies(svc.UserInvitations(username)), ApiJson.Default.ListInvitationBody);
-        });
-        api.MapGet("/channels/{id}/invitations", (string id, HttpContext ctx, ChannelService svc) =>
-            Json(InvitationBodies(svc.Invitations(ParseId(id), RequestAuth.FromHeaders(ctx.Request, false))), ApiJson.Default.ListInvitationBody));
-        api.MapGet("/channels/{id}/members", (string id, HttpContext ctx, ChannelService svc) =>
-            Json(svc.Members(ParseId(id), RequestAuth.FromHeaders(ctx.Request, true)).Select(m => new MemberBody { Username = m.Username, Role = m.Role, JoinedAt = m.JoinedAt }).ToList(), ApiJson.Default.ListMemberBody));
-        api.MapPost("/channels/{id}/invitations", async (string id, HttpContext ctx, ChannelService svc, CancellationToken ct) =>
-        {
-            var req = await ReadJson(ctx.Request, ApiJson.Default.InvitationRequest, ct);
-            var username = NormalizeUsername(req.Username);
-            if (accounts.GetPublicKey(username) is null) throw new WebDropException(ErrorCode.NotFound);
-            svc.InviteUser(ParseId(id), RequestAuth.FromHeaders(ctx.Request, false), username, req.Payload); return Results.NoContent();
-        });
-        api.MapDelete("/channels/{id}/invitations/{username}", (string id, string username, HttpContext ctx, ChannelService svc) =>
-        {
-            svc.RevokeInvitation(ParseId(id), RequestAuth.FromHeaders(ctx.Request, false), NormalizeUsername(username)); return Results.NoContent();
-        });
-
-    }
-}

server/src/WebDrop.Api/Endpoints/Endpoints.Accounts.cs

@@ -1,3 +1,4 @@
+using Microsoft.AspNetCore.Http.Features;
 using WebDrop.Core;
 using WebDrop.Storage;
 
@@ -7,6 +8,29 @@ public static partial class Endpoints
 {
     private static void MapAccounts(RouteGroupBuilder api, SqliteAccountStore accounts)
     {
+        api.MapGet("/accounts/profile", (HttpContext ctx) =>
+        {
+            if (!TryAccount(ctx, accounts, out var username)) throw new WebDropException(ErrorCode.AccountRequired);
+            return Json(accounts.Profile(username).WithoutAvatar(), ApiJson.Default.AccountProfile);
+        });
+        // 头像单独取:默认给有损的缩略图(列表、聊天用),size=full 才是原图(预览时)。带 ETag,没变化时只回 304。需要登录账号
+        api.MapGet("/accounts/users/{username}/avatar", (string username, HttpContext ctx, ChannelService svc) =>
+        {
+            if (!TryAccount(ctx, accounts, out var viewer)) throw new WebDropException(ErrorCode.AccountRequired);
+            // 只有和对方同在一个空间(或就是自己)才能看头像,不能靠猜用户名批量抓取
+            if (!svc.SharesSpace(viewer, NormalizeUsername(username))) throw new WebDropException(ErrorCode.NotFound);
+            return AvatarResult(ctx, accounts.ProfileAvatar(NormalizeUsername(username), ctx.Request.Query["size"] == "full"));
+        });
+        api.MapPatch("/accounts/profile", async (HttpContext ctx, ChannelService svc, CancellationToken ct) =>
+        {
+            if (!TryAccount(ctx, accounts, out var username)) throw new WebDropException(ErrorCode.AccountRequired);
+            // 动图头像比其他请求大得多,单独放宽(全局上限 2 MB)
+            if (ctx.Features.Get<IHttpMaxRequestBodySizeFeature>() is { IsReadOnly: false } size) size.MaxRequestBodySize = 8 * 1024 * 1024;
+            var req = await ReadJsonCompressed(ctx.Request, ApiJson.Default.AccountProfileRequest, 12 * 1024 * 1024, ct);
+            var profile = accounts.UpdateProfile(username, req.DisplayName, req.Avatar, req.AvatarThumb, req.KeepAvatar);
+            svc.AccountProfileChanged(username);
+            return Json(profile.WithoutAvatar(), ApiJson.Default.AccountProfile);
+        });
         api.MapPost("/accounts", async (HttpContext ctx, CancellationToken ct) =>
         {
             var req = await ReadJson(ctx.Request, ApiJson.Default.AccountRegisterRequest, ct);
@@ -15,7 +39,8 @@ public static partial class Endpoints
             var verifier = DecodeBase64(req.Verifier, 32, 32);
             var vault = DecodeBase64(req.Vault, 28, 1_300_000);
             ValidatePublicKey(req.PublicKey);
-            if (!accounts.Register(username, salt, verifier, vault, req.PublicKey)) return Json(new ErrorBody { Error = "username_unavailable" }, ApiJson.Default.ErrorBody, StatusCodes.Status409Conflict);
+            ValidatePublicKey(req.SigningPublicKey);
+            if (!accounts.Register(username, salt, verifier, vault, req.PublicKey, req.SigningPublicKey)) return Json(new ErrorBody { Error = "username_unavailable" }, ApiJson.Default.ErrorBody, StatusCodes.Status409Conflict);
             return Results.NoContent();
         }).RequireRateLimiting(CreatePolicy);
 
@@ -59,11 +84,34 @@ public static partial class Endpoints
             if (req.Name is null || !accounts.RenameDevice(username, id, req.Name.Trim())) throw new WebDropException(ErrorCode.BadRequest);
             return Results.NoContent();
         });
+        api.MapPut("/accounts/devices/signing-key", async (HttpContext ctx, SqliteAccountStore accountStore, CancellationToken ct) =>
+        {
+            if (!TryAccount(ctx, accountStore, out var username)) throw new WebDropException(ErrorCode.AccountRequired);
+            var req = await ReadJson(ctx.Request, ApiJson.Default.AccountDeviceSigningRequest, ct);
+            var token = ctx.Request.Headers["X-WD-Account"].ToString();
+            var deviceId = accountStore.SessionDevice(token);
+            if (deviceId is null || !string.Equals(deviceId, req.DeviceId, StringComparison.OrdinalIgnoreCase)) throw new WebDropException(ErrorCode.Forbidden);
+            ValidatePublicKey(req.PublicKey);
+            var rootKey = accountStore.GetSigningPublicKey(username);
+            if (rootKey is null) throw new WebDropException(ErrorCode.BadRequest);
+            using var root = System.Text.Json.JsonDocument.Parse(rootKey);
+            var rootObject = root.RootElement;
+            if (!Codec.TryDecodeExact(rootObject.GetProperty("x").GetString(), 32, out var rootX)
+                || !Codec.TryDecodeExact(rootObject.GetProperty("y").GetString(), 32, out var rootY)) throw new WebDropException(ErrorCode.BadRequest);
+            using var device = System.Text.Json.JsonDocument.Parse(req.PublicKey);
+            var deviceObject = device.RootElement;
+            if (!Codec.TryDecodeExact(deviceObject.GetProperty("x").GetString(), 32, out var deviceX)
+                || !Codec.TryDecodeExact(deviceObject.GetProperty("y").GetString(), 32, out var deviceY)) throw new WebDropException(ErrorCode.BadRequest);
+            var payload = SignatureCodec.DeviceCertificatePayload(username, deviceId, deviceX, deviceY);
+            var signature = DecodeBase64(req.Signature, 64, 64);
+            if (!SignatureCodec.VerifyP256(rootX, rootY, "device.certificate", payload, signature)) throw new WebDropException(ErrorCode.Forbidden);
+            if (!accountStore.SaveDeviceSigningKey(username, deviceId, req.PublicKey, signature)) throw new WebDropException(ErrorCode.Forbidden);
+            return Results.NoContent();
+        });
         api.MapDelete("/accounts/devices/{id}", (string id, HttpContext ctx, ChannelService svc) =>
         {
             if (!TryAccount(ctx, accounts, out var username)) throw new WebDropException(ErrorCode.AccountRequired);
             accounts.RevokeDevice(username, id);
-            svc.ReleaseAccountDevice(username, id);
             return Results.NoContent();
         });
 

server/src/WebDrop.Api/Endpoints/Endpoints.ChannelAccess.cs

@@ -0,0 +1,117 @@
+using WebDrop.Core;
+using WebDrop.Storage;
+
+namespace WebDrop.Api;
+
+public static partial class Endpoints
+{
+    private static void MapChannelAccess(RouteGroupBuilder api, SqliteAccountStore accounts)
+    {
+        api.MapGet("/accounts/spaces", (HttpContext ctx, ChannelService svc) =>
+        {
+            if (!TryAccount(ctx, accounts, out var username)) throw new WebDropException(ErrorCode.AccountRequired);
+            return Json(svc.AccountSpaces(username).ToList(), ApiJson.Default.ListChannelInfo);
+        });
+        // 空间列表的实时提示:账号所在空间有新内容就推一条 {id,last_seq}。只含序号,不含内容
+        api.MapGet("/accounts/spaces/events", async (HttpContext ctx, ChannelService svc, ChannelHub hub) =>
+        {
+            if (!TryAccount(ctx, accounts, out var username)) throw new WebDropException(ErrorCode.AccountRequired);
+            var ct = ctx.RequestAborted;
+            ctx.Response.ContentType = "text/event-stream";
+            ctx.Response.Headers["X-Accel-Buffering"] = "no";
+            await ctx.Response.StartAsync(ct);
+            var sent = new Dictionary<Id16, long>();
+            try
+            {
+                while (!ct.IsCancellationRequested)
+                {
+                    // 每次唤醒都重新核对登录:退出登录、被移除设备后,这条流立刻结束
+                    if (!TryAccount(ctx, accounts, out var current) || current != username)
+                    {
+                        await ctx.Response.WriteAsync("event: error\ndata: {\"error\":\"account_required\"}\n\n", ct);
+                        break;
+                    }
+                    var changed = hub.AnyAdvanced;
+                    foreach (var id in svc.AccountSpaceIds(username))
+                    {
+                        var seq = hub.AdvancedSeq(id);
+                        // 第一次只记下当前值:连接建立前的进展客户端已经从列表里拿到了
+                        if (!sent.TryGetValue(id, out var known)) { sent[id] = seq; continue; }
+                        if (seq <= known) continue;
+                        sent[id] = seq;
+                        await ctx.Response.WriteAsync($"event: space\ndata: {{\"id\":\"{id.ToBase64Url()}\",\"last_seq\":{seq}}}\n\n", ct);
+                    }
+                    await ctx.Response.Body.FlushAsync(ct);
+                    var idle = Task.Delay(TimeSpan.FromSeconds(20), ct);
+                    // 久无变化就发心跳,客户端据此判断连接还活着
+                    if (await Task.WhenAny(changed, idle) == idle) { await ctx.Response.WriteAsync("event: ping\ndata: 1\n\n", ct); await ctx.Response.Body.FlushAsync(ct); }
+                }
+            }
+            catch (OperationCanceledException) { }
+            return Results.Empty;
+        });
+        api.MapGet("/accounts/channels", (HttpContext ctx, ChannelService svc) =>
+        {
+            if (!TryAccount(ctx, accounts, out var username)) throw new WebDropException(ErrorCode.AccountRequired);
+            var packages = svc.AccountChannels(username).Select(k => new AccountChannelBody
+            {
+                ChannelId = k.ChannelId.ToBase64Url(), Role = k.Role, Payload = k.Payload, CreatedAt = k.CreatedAt,
+            }).ToList();
+            return Json(packages, ApiJson.Default.ListAccountChannelBody);
+        });
+        api.MapPut("/channels/{id}/key-package", async (string id, HttpContext ctx, ChannelService svc, CancellationToken ct) =>
+        {
+            var req = await ReadJson(ctx.Request, ApiJson.Default.KeyPackageRequest, ct);
+            svc.SaveOwnerKeyPackage(ParseId(id), RequestAuth.FromHeaders(ctx.Request, false), req.Payload);
+            return Results.NoContent();
+        });
+        api.MapGet("/accounts/users/{username}/key", (string username, HttpContext ctx) =>
+        {
+            if (!TryAccount(ctx, accounts, out _)) throw new WebDropException(ErrorCode.AccountRequired);
+            var key = accounts.GetPublicKey(NormalizeUsername(username));
+            if (key is null) throw new WebDropException(ErrorCode.NotFound);
+            return Json(new PublicKeyBody { PublicKey = key, SigningPublicKey = accounts.GetSigningPublicKey(NormalizeUsername(username)) }, ApiJson.Default.PublicKeyBody);
+        });
+        api.MapGet("/accounts/invitations", (HttpContext ctx, ChannelService svc) =>
+        {
+            if (!TryAccount(ctx, accounts, out var username)) throw new WebDropException(ErrorCode.AccountRequired);
+            return Json(InvitationBodies(svc.UserInvitations(username)), ApiJson.Default.ListInvitationBody);
+        });
+        api.MapGet("/channels/{id}/invitations", (string id, HttpContext ctx, ChannelService svc) =>
+            Json(svc.InvitationsView(ParseId(id), RequestAuth.FromHeaders(ctx.Request, false)).Select(view => new InvitationBody
+            { ChannelId = view.Invitation.ChannelId.ToBase64Url(), Username = view.Invitation.Username, Payload = view.Invitation.Payload, CreatedAt = view.Invitation.CreatedAt, CanRevoke = view.CanRevoke }).ToList(), ApiJson.Default.ListInvitationBody));
+        api.MapGet("/channels/{id}/invitations/{username}/crypto-plan", (string id, string username, HttpContext ctx, ChannelService svc, SqliteAccountStore accountStore) =>
+        {
+            username = NormalizeUsername(username);
+            if (accountStore.GetPublicKey(username) is null) throw new WebDropException(ErrorCode.NotFound);
+            return Json(svc.InvitationPlan(ParseId(id), RequestAuth.FromHeaders(ctx.Request, false), username), ApiJson.Default.InvitationCryptoPlan);
+        });
+        api.MapGet("/channels/{id}/members", (string id, HttpContext ctx, ChannelService svc, ChannelHub hub) =>
+        {
+            var channelId = ParseId(id);
+            var members = svc.MembersView(channelId, RequestAuth.FromHeaders(ctx.Request, false)).Select(view =>
+            {
+                var member = view.Member;
+                var (online, onlineDevices) = hub.Presence(channelId, member.Username);
+                // 设备是账号的属性:总数取账号的登录设备,在线数取该账号在本频道有订阅的设备
+                var devices = accounts.Devices(member.Username, null);
+                return new MemberBody { Username = member.Username, Role = member.Role, JoinedAt = member.JoinedAt,
+                    Online = online, Devices = Math.Max(devices.Count, onlineDevices), OnlineDevices = onlineDevices,
+                    LastSeen = devices.Count == 0 ? 0 : devices.Max(device => device.LastSeen), CanRemove = view.CanRemove };
+            }).ToList();
+            return Json(members, ApiJson.Default.ListMemberBody);
+        });
+        api.MapPost("/channels/{id}/invitations", async (string id, HttpContext ctx, ChannelService svc, CancellationToken ct) =>
+        {
+            var req = await ReadJson(ctx.Request, ApiJson.Default.InvitationRequest, ct);
+            var username = NormalizeUsername(req.Username);
+            if (accounts.GetPublicKey(username) is null) throw new WebDropException(ErrorCode.NotFound);
+            svc.InviteUser(ParseId(id), RequestAuth.FromHeaders(ctx.Request, false), username, req.Payload, req.DomainEnvelopes ?? []); return Results.NoContent();
+        });
+        api.MapDelete("/channels/{id}/invitations/{username}", (string id, string username, HttpContext ctx, ChannelService svc) =>
+        {
+            svc.RevokeInvitation(ParseId(id), RequestAuth.FromHeaders(ctx.Request, false), NormalizeUsername(username)); return Results.NoContent();
+        });
+
+    }
+}

server/src/WebDrop.Api/Endpoints/Endpoints.Files.cs

@@ -0,0 +1,58 @@
+using WebDrop.Core;
+using WebDrop.Storage;
+
+namespace WebDrop.Api;
+
+public static partial class Endpoints
+{
+    /// <summary>
+    /// 文件服务的票据:权限由空间决定,通过后给客户端一张短期票据,客户端拿着它直接找文件服务。
+    /// create 是所有者/管理员创建文件域;put/get 是按频道权限上传、下载某个条目。
+    /// </summary>
+    private static void MapFiles(RouteGroupBuilder api)
+    {
+        // 一次登记整个文件:请求体 = 末帧的 26 字节头部 + 每一帧的 [负载长度 u32 大端][整帧 SHA-256 32 字节]。
+        // 字节早已存进文件域;逐帧登记要为每个 1 MiB 往返一次,这里一次搞定
+        api.MapPost("/channels/{id}/files", async (string id, HttpContext ctx, ChannelService svc, SqliteAccountStore accountStore, ServerLimits limits, CancellationToken ct) =>
+        {
+            var channelId = ParseId(id);
+            var creds = RequestAuth.FromHeaders(ctx.Request, requireEndpoint: false);
+            long? maxDownloads = ParseMaxDownloads(ctx.Request.Headers["X-WD-Max-Downloads"].ToString());
+            const int EntrySize = 36;
+            int max = Envelope.HeaderSize + limits.MaxFramesPerItem * EntrySize;
+            if (ctx.Features.Get<Microsoft.AspNetCore.Http.Features.IHttpMaxRequestBodySizeFeature>() is { IsReadOnly: false } size) size.MaxRequestBodySize = max;
+            byte[] body = await ReadBody(ctx.Request, max, ct);
+            if (body.Length < Envelope.HeaderSize + EntrySize || (body.Length - Envelope.HeaderSize) % EntrySize != 0) throw new WebDropException(ErrorCode.BadRequest);
+            var header = body.AsMemory(0, Envelope.HeaderSize);
+            var entries = new List<ChannelService.FrameEntry>((body.Length - Envelope.HeaderSize) / EntrySize);
+            for (int at = Envelope.HeaderSize; at < body.Length; at += EntrySize)
+                entries.Add(new ChannelService.FrameEntry((int)System.Buffers.Binary.BinaryPrimitives.ReadUInt32BigEndian(body.AsSpan(at, 4)), body.AsSpan(at + 4, 32).ToArray()));
+            var signedEvent = ParseSignedContentEvent(ctx.Request, accountStore, channelId, creds, header.ToArray());
+            var result = svc.RegisterFileItem(channelId, creds, header, entries, maxDownloads, signedEvent);
+            return Json(result, ApiJson.Default.AppendResult, result.Created ? StatusCodes.Status201Created : StatusCodes.Status200OK);
+        });
+
+        api.MapPost("/spaces/{id}/file-grants", async (string id, HttpContext ctx, ChannelService svc, CancellationToken ct) =>
+        {
+            var spaceId = ParseId(id);
+            var creds = RequestAuth.FromHeaders(ctx.Request, requireEndpoint: false);
+            var req = await ReadJson(ctx.Request, ApiJson.Default.FileGrantRequest, ct);
+            FileGrant grant;
+            if (req.Op == "create") grant = svc.IssueCreateGrant(spaceId, creds);
+            else if (req.Op == "domain") grant = svc.IssueDomainGrant(spaceId, creds, req.Channel ?? throw new WebDropException(ErrorCode.BadRequest));
+            else
+            {
+                if (req.Item is null || req.From is < 0 or > uint.MaxValue) throw new WebDropException(ErrorCode.BadRequest);
+                var item = ParseId(req.Item);
+                grant = req.Op switch
+                {
+                    "put" => svc.IssueUploadGrant(spaceId, creds, item),
+                    "get" => svc.IssueDownloadGrant(spaceId, creds, item, (uint)req.From),
+                    "delete" => svc.IssueDeleteGrant(spaceId, creds, item),
+                    _ => throw new WebDropException(ErrorCode.BadRequest),
+                };
+            }
+            return Json(new FileGrantBody { Url = grant.Url, Domain = grant.Domain, Ticket = grant.Ticket, ExpiresAt = grant.ExpiresAt }, ApiJson.Default.FileGrantBody);
+        });
+    }
+}

server/src/WebDrop.Api/Endpoints/Endpoints.Passkeys.cs

@@ -0,0 +1,93 @@
+using System.Security.Cryptography;
+using System.Text.Json;
+using Microsoft.AspNetCore.Identity;
+using WebDrop.Core;
+using WebDrop.Storage;
+
+namespace WebDrop.Api;
+
+public static partial class Endpoints
+{
+    private static PasskeyInfoBody PasskeyInfo(StoredPasskey p) => new() { Id = p.Id, Name = p.Name, PrfSalt = p.PrfSalt, CanRecover = p.KeyEnvelope is not null, CreatedAt = p.CreatedAt };
+    private static void ValidateRecoveryEnvelope(string? value)
+    {
+        if (value is not null) _ = DecodeBase64(value, 28, 512);
+    }
+    private static void MapPasskeys(RouteGroupBuilder api, SqliteAccountStore accounts)
+    {
+        api.MapGet("/accounts/passkeys", (HttpContext ctx) =>
+        {
+            if (!TryAccount(ctx, accounts, out var username)) throw new WebDropException(ErrorCode.AccountRequired);
+            return Json(accounts.Passkeys(username).Select(PasskeyInfo).ToList(), ApiJson.Default.ListPasskeyInfoBody);
+        });
+        api.MapDelete("/accounts/passkeys/{id}", (string id, HttpContext ctx) =>
+        {
+            if (!TryAccount(ctx, accounts, out var username)) throw new WebDropException(ErrorCode.AccountRequired);
+            accounts.RemovePasskey(id, username); return Results.NoContent();
+        });
+        api.MapPost("/accounts/passkeys/register/options", async (HttpContext ctx, IPasskeyHandler<PasskeyAccount> handler, PasskeyCeremonies ceremonies, CancellationToken ct) =>
+        {
+            if (!TryAccount(ctx, accounts, out var username)) throw new WebDropException(ErrorCode.AccountRequired);
+            var req = await ReadJson(ctx.Request, ApiJson.Default.PasskeyBeginRequest, ct);
+            if (NormalizeUsername(req.Username) != username || req.Verifier is null || !accounts.VerifyLogin(username, DecodeBase64(req.Verifier, 32, 32))) throw new WebDropException(ErrorCode.Unauthorized);
+            var result = await handler.MakeCreationOptionsAsync(new() { Id = username, Name = username, DisplayName = accounts.Profile(username).DisplayName }, ctx);
+            var salt = Codec.Encode(RandomNumberGenerator.GetBytes(32));
+            var id = ceremonies.Put(new(username, "register", result.AttestationState ?? throw new WebDropException(ErrorCode.BadRequest), salt, PasskeyCeremonies.Hash(ctx.Request.Headers["X-WD-Account"].ToString()), DateTimeOffset.UtcNow.AddMinutes(2)));
+            return Json(new PasskeyOptionsBody { Id = id, Options = result.CreationOptionsJson, PrfSalt = salt }, ApiJson.Default.PasskeyOptionsBody);
+        }).RequireRateLimiting(CreatePolicy);
+        api.MapPost("/accounts/passkeys/register", async (HttpContext ctx, IPasskeyHandler<PasskeyAccount> handler, PasskeyCeremonies ceremonies, CancellationToken ct) =>
+        {
+            if (!TryAccount(ctx, accounts, out var username)) throw new WebDropException(ErrorCode.AccountRequired);
+            var req = await ReadJson(ctx.Request, ApiJson.Default.PasskeyFinishRequest, ct);
+            var state = ceremonies.Take(req.Id, username, "register", ctx.Request.Headers["X-WD-Account"].ToString());
+            if (NormalizeUsername(req.Username) != username || req.Credential.Length > 40_000 || req.Name is null || req.Name.Trim().Length is < 1 or > 80 || req.Name.Any(char.IsControl)) throw new WebDropException(ErrorCode.BadRequest);
+            ValidateRecoveryEnvelope(req.KeyEnvelope);
+            var result = await handler.PerformAttestationAsync(new() { HttpContext = ctx, CredentialJson = req.Credential, AttestationState = state.State });
+            if (!result.Succeeded || result.UserEntity?.Id != username || result.Passkey is null) throw new WebDropException(ErrorCode.BadRequest);
+            result.Passkey.Name = req.Name.Trim();
+            var row = new StoredPasskey(Codec.Encode(result.Passkey.CredentialId), username, result.Passkey.Name,
+                JsonSerializer.Serialize(result.Passkey, PasskeyStorageJson.Default.UserPasskeyInfo), state.PrfSalt, req.KeyEnvelope, DateTimeOffset.UtcNow.ToUnixTimeMilliseconds());
+            accounts.AddPasskey(row); return Json(PasskeyInfo(row), ApiJson.Default.PasskeyInfoBody, 201);
+        }).RequireRateLimiting(CreatePolicy);
+        api.MapPost("/accounts/passkeys/login/options", async (HttpContext ctx, IPasskeyHandler<PasskeyAccount> handler, PasskeyCeremonies ceremonies, CancellationToken ct) =>
+        {
+            var req = await ReadJson(ctx.Request, ApiJson.Default.AccountSaltRequest, ct); var username = NormalizeUsername(req.Username);
+            var options = await handler.MakeRequestOptionsAsync(new PasskeyAccount(username), ctx);
+            var id = ceremonies.Put(new(username, "login", options.AssertionState ?? throw new WebDropException(ErrorCode.BadRequest), "", null, DateTimeOffset.UtcNow.AddMinutes(2)));
+            return Json(new PasskeyOptionsBody { Id = id, Options = options.RequestOptionsJson, Credentials = accounts.Passkeys(username).Select(PasskeyInfo).ToList() }, ApiJson.Default.PasskeyOptionsBody);
+        }).RequireRateLimiting(CreatePolicy);
+        api.MapPost("/accounts/passkeys/login", async (HttpContext ctx, IPasskeyHandler<PasskeyAccount> handler, UserManager<PasskeyAccount> manager, PasskeyCeremonies ceremonies, CancellationToken ct) =>
+        {
+            var req = await ReadJson(ctx.Request, ApiJson.Default.PasskeyFinishRequest, ct); var username = NormalizeUsername(req.Username);
+            var state = ceremonies.Take(req.Id, username, "login", null);
+            if (req.Credential.Length > 40_000 || req.DeviceId is null || req.DeviceName is null) throw new WebDropException(ErrorCode.BadRequest);
+            var result = await handler.PerformAssertionAsync(new() { HttpContext = ctx, CredentialJson = req.Credential, AssertionState = state.State });
+            if (!result.Succeeded || result.User?.Username != username || result.Passkey is null) throw new WebDropException(ErrorCode.Unauthorized);
+            var id = Codec.Encode(result.Passkey.CredentialId); var row = accounts.Passkey(id) ?? throw new WebDropException(ErrorCode.Unauthorized);
+            var updated = await manager.AddOrUpdatePasskeyAsync(result.User, result.Passkey);
+            if (!updated.Succeeded) throw new WebDropException(ErrorCode.Unauthorized);
+            var token = accounts.CreateDeviceSession(username, req.DeviceId, req.DeviceName) ?? throw new WebDropException(ErrorCode.BadRequest);
+            return Json(new PasskeySessionBody { Username = username, Token = token, CredentialId = id, PrfSalt = row.PrfSalt, KeyEnvelope = row.KeyEnvelope }, ApiJson.Default.PasskeySessionBody);
+        }).RequireRateLimiting(CreatePolicy);
+        api.MapPost("/accounts/passkeys/recovery/options", async (HttpContext ctx, IPasskeyHandler<PasskeyAccount> handler, PasskeyCeremonies ceremonies) =>
+        {
+            if (!TryAccount(ctx, accounts, out var username)) throw new WebDropException(ErrorCode.AccountRequired);
+            var options = await handler.MakeRequestOptionsAsync(new PasskeyAccount(username), ctx);
+            var id = ceremonies.Put(new(username, "recovery", options.AssertionState ?? throw new WebDropException(ErrorCode.BadRequest), "", PasskeyCeremonies.Hash(ctx.Request.Headers["X-WD-Account"].ToString()), DateTimeOffset.UtcNow.AddMinutes(2)));
+            return Json(new PasskeyOptionsBody { Id = id, Options = options.RequestOptionsJson, Credentials = accounts.Passkeys(username).Select(PasskeyInfo).ToList() }, ApiJson.Default.PasskeyOptionsBody);
+        }).RequireRateLimiting(CreatePolicy);
+        api.MapPut("/accounts/passkeys/recovery", async (HttpContext ctx, IPasskeyHandler<PasskeyAccount> handler, UserManager<PasskeyAccount> manager, PasskeyCeremonies ceremonies, CancellationToken ct) =>
+        {
+            if (!TryAccount(ctx, accounts, out var username)) throw new WebDropException(ErrorCode.AccountRequired);
+            var req = await ReadJson(ctx.Request, ApiJson.Default.PasskeyEnvelopeRequest, ct);
+            var state = ceremonies.Take(req.Id, username, "recovery", ctx.Request.Headers["X-WD-Account"].ToString());
+            if (NormalizeUsername(req.Username) != username || req.Credential.Length > 40_000) throw new WebDropException(ErrorCode.BadRequest);
+            ValidateRecoveryEnvelope(req.KeyEnvelope);
+            var result = await handler.PerformAssertionAsync(new() { HttpContext = ctx, CredentialJson = req.Credential, AssertionState = state.State });
+            if (!result.Succeeded || result.User?.Username != username || result.Passkey is null) throw new WebDropException(ErrorCode.Unauthorized);
+            if (!(await manager.AddOrUpdatePasskeyAsync(result.User, result.Passkey)).Succeeded) throw new WebDropException(ErrorCode.Unauthorized);
+            accounts.UpdatePasskeyEnvelope(Codec.Encode(result.Passkey.CredentialId), username, req.KeyEnvelope);
+            return Results.NoContent();
+        }).RequireRateLimiting(CreatePolicy);
+    }
+}

server/src/WebDrop.Api/Endpoints/Endpoints.Workspace.cs

@@ -0,0 +1,89 @@
+using WebDrop.Core;
+using WebDrop.Storage;
+
+namespace WebDrop.Api;
+
+public static partial class Endpoints
+{
+    private static void MapWorkspace(RouteGroupBuilder api, SqliteAccountStore accounts)
+    {
+        // 成员资料:发过内容的作者加上空间里所有成员(没发过内容的成员也要能显示头像和名字)
+        WorkspaceBody View(ChannelService service, Id16 space, WorkspaceState state) => new()
+        {
+            Structure = state,
+            People = state.Locations.Select(l => l.AuthorAccount).Where(u => u is not null).Select(u => u!)
+                .Concat(service.MemberAccounts(space)).Distinct(StringComparer.OrdinalIgnoreCase)
+                .Select(u => accounts.Profile(u).WithoutAvatar()).ToList(),
+        };
+        api.MapGet("/spaces/{id}/structure", (string id, HttpContext ctx, ChannelService svc) =>
+            Json(View(svc, ParseId(id), svc.GetWorkspace(ParseId(id), RequestAuth.FromHeaders(ctx.Request, false))), ApiJson.Default.WorkspaceBody));
+        api.MapPost("/spaces/{id}/channels", async (string id, HttpContext ctx, ChannelService svc, CancellationToken ct) =>
+        {
+            var req = await ReadJson(ctx.Request, ApiJson.Default.WorkspaceChannelRequest, ct);
+            var created = svc.CreateWorkspaceChannelResult(ParseId(id), RequestAuth.FromHeaders(ctx.Request, false), req.Name, req.GroupId, req.FileDomain);
+            return Json(new WorkspaceChannelCreatedBody { Workspace = View(svc, ParseId(id), created.State), Channel = created.Channel }, ApiJson.Default.WorkspaceChannelCreatedBody, 201);
+        });
+        api.MapPatch("/spaces/{id}/channels/{channelId}", async (string id, string channelId, HttpContext ctx, ChannelService svc, CancellationToken ct) =>
+        {
+            var req = await ReadJson(ctx.Request, ApiJson.Default.WorkspaceNameRequest, ct);
+            return Json(View(svc, ParseId(id), svc.RenameWorkspaceChannel(ParseId(id), RequestAuth.FromHeaders(ctx.Request, false), channelId, req.Name)), ApiJson.Default.WorkspaceBody);
+        });
+        api.MapPut("/spaces/{id}/channels/{channelId}/file-domain", async (string id, string channelId, HttpContext ctx, ChannelService svc, CancellationToken ct) =>
+        {
+            var req = await ReadJson(ctx.Request, ApiJson.Default.WorkspaceFileDomainRequest, ct);
+            return Json(View(svc, ParseId(id), svc.SetWorkspaceChannelFileDomain(ParseId(id), RequestAuth.FromHeaders(ctx.Request, false), channelId, req.FileDomain)), ApiJson.Default.WorkspaceBody);
+        });
+        api.MapPut("/spaces/{id}/channels/{channelId}/group", async (string id, string channelId, HttpContext ctx, ChannelService svc, CancellationToken ct) =>
+        {
+            var req = await ReadJson(ctx.Request, ApiJson.Default.WorkspaceGroupRequest, ct);
+            return Json(View(svc, ParseId(id), svc.GroupWorkspaceChannel(ParseId(id), RequestAuth.FromHeaders(ctx.Request, false), channelId, req.GroupId)), ApiJson.Default.WorkspaceBody);
+        });
+        api.MapPost("/spaces/{id}/groups", async (string id, HttpContext ctx, ChannelService svc, CancellationToken ct) =>
+        {
+            var req = await ReadJson(ctx.Request, ApiJson.Default.WorkspaceNameRequest, ct);
+            var created = svc.CreateWorkspaceGroupResult(ParseId(id), RequestAuth.FromHeaders(ctx.Request, false), req.Name);
+            return Json(new WorkspaceGroupCreatedBody { Workspace = View(svc, ParseId(id), created.State), Group = created.Group }, ApiJson.Default.WorkspaceGroupCreatedBody, 201);
+        });
+        api.MapPatch("/spaces/{id}/groups/{groupId}", async (string id, string groupId, HttpContext ctx, ChannelService svc, CancellationToken ct) =>
+        {
+            var req = await ReadJson(ctx.Request, ApiJson.Default.WorkspaceNameRequest, ct);
+            return Json(View(svc, ParseId(id), svc.RenameWorkspaceGroup(ParseId(id), RequestAuth.FromHeaders(ctx.Request, false), groupId, req.Name)), ApiJson.Default.WorkspaceBody);
+        });
+        api.MapDelete("/spaces/{id}/groups/{groupId}", (string id, string groupId, HttpContext ctx, ChannelService svc) =>
+            Json(View(svc, ParseId(id), svc.DeleteWorkspaceGroup(ParseId(id), RequestAuth.FromHeaders(ctx.Request, false), groupId)), ApiJson.Default.WorkspaceBody));
+        api.MapPost("/spaces/{id}/roles", async (string id, HttpContext ctx, ChannelService svc, CancellationToken ct) =>
+        {
+            var req = await ReadJson(ctx.Request, ApiJson.Default.WorkspaceRoleRequest, ct);
+            var created = svc.CreateWorkspaceRoleResult(ParseId(id), RequestAuth.FromHeaders(ctx.Request, false), req.Name, req.Prefix, req.Suffix, req.Color, req.Permissions);
+            return Json(new WorkspaceRoleCreatedBody { Workspace = View(svc, ParseId(id), created.State), Role = created.Role }, ApiJson.Default.WorkspaceRoleCreatedBody, 201);
+        });
+        api.MapPatch("/spaces/{id}/roles/{roleId}", async (string id, string roleId, HttpContext ctx, ChannelService svc, CancellationToken ct) =>
+        {
+            var req = await ReadJson(ctx.Request, ApiJson.Default.WorkspaceRoleRequest, ct);
+            return Json(View(svc, ParseId(id), svc.UpdateWorkspaceRole(ParseId(id), RequestAuth.FromHeaders(ctx.Request, false), roleId, req.Name, req.Prefix, req.Suffix, req.Color, req.Permissions)), ApiJson.Default.WorkspaceBody);
+        });
+        api.MapDelete("/spaces/{id}/roles/{roleId}", (string id, string roleId, HttpContext ctx, ChannelService svc) =>
+            Json(View(svc, ParseId(id), svc.DeleteWorkspaceRole(ParseId(id), RequestAuth.FromHeaders(ctx.Request, false), roleId)), ApiJson.Default.WorkspaceBody));
+        api.MapPut("/spaces/{id}/roles/{roleId}/members", async (string id, string roleId, HttpContext ctx, ChannelService svc, CancellationToken ct) =>
+        {
+            var req = await ReadJson(ctx.Request, ApiJson.Default.WorkspaceRoleMembersRequest, ct);
+            return Json(View(svc, ParseId(id), svc.SetWorkspaceRoleMembers(ParseId(id), RequestAuth.FromHeaders(ctx.Request, false), roleId, req.Members)), ApiJson.Default.WorkspaceBody);
+        });
+        api.MapPost("/spaces/{id}/folders", async (string id, HttpContext ctx, ChannelService svc, CancellationToken ct) =>
+        {
+            var req = await ReadJson(ctx.Request, ApiJson.Default.WorkspaceFolderRequest, ct);
+            return Json(View(svc, ParseId(id), svc.CreateWorkspaceFolder(ParseId(id), RequestAuth.FromHeaders(ctx.Request, false), req.ThreadId, req.ParentId, req.Name)), ApiJson.Default.WorkspaceBody, 201);
+        });
+        api.MapPatch("/spaces/{id}/folders/{folderId}", async (string id, string folderId, HttpContext ctx, ChannelService svc, CancellationToken ct) =>
+        {
+            var req = await ReadJson(ctx.Request, ApiJson.Default.WorkspaceNameRequest, ct);
+            return Json(View(svc, ParseId(id), svc.RenameWorkspaceFolder(ParseId(id), RequestAuth.FromHeaders(ctx.Request, false), folderId, req.Name)), ApiJson.Default.WorkspaceBody);
+        });
+        api.MapPut("/spaces/{id}/locations", async (string id, HttpContext ctx, ChannelService svc, CancellationToken ct) =>
+        {
+            var req = await ReadJson(ctx.Request, ApiJson.Default.WorkspaceMoveRequest, ct);
+            if (req.ItemIds is null) throw new WebDropException(ErrorCode.BadRequest);
+            return Json(View(svc, ParseId(id), svc.MoveWorkspaceItems(ParseId(id), RequestAuth.FromHeaders(ctx.Request, false), req.ItemIds, req.ThreadId, req.FolderId)), ApiJson.Default.WorkspaceBody);
+        });
+    }
+}

server/src/WebDrop.Api/Endpoints/Endpoints.WorkspaceCrypto.cs

@@ -0,0 +1,32 @@
+using System.Text.Json.Serialization;
+using WebDrop.Core;
+
+namespace WebDrop.Api;
+
+public sealed class ChannelHistoryRequest
+{
+    [JsonPropertyName("chatHistory")] public bool ChatHistory { get; init; }
+    [JsonPropertyName("filesHistory")] public bool FilesHistory { get; init; }
+}
+public static partial class Endpoints
+{
+    private static void MapWorkspaceCrypto(RouteGroupBuilder api)
+    {
+        api.MapGet("/spaces/{id}/crypto", (string id, HttpContext ctx, ChannelService svc) => Json(svc.ReadCrypto(ParseId(id), RequestAuth.FromHeaders(ctx.Request, false)), ApiJson.Default.CryptoState));
+        api.MapPut("/spaces/{id}/crypto/domains", async (string id, HttpContext ctx, ChannelService svc, CancellationToken ct) =>
+        {
+            var req = await ReadJson(ctx.Request, ApiJson.Default.DomainPublishRequest, ct);
+            svc.PublishDomain(ParseId(id), RequestAuth.FromHeaders(ctx.Request, false), req); return Results.NoContent();
+        });
+        api.MapPost("/spaces/{id}/crypto/objects", async (string id, HttpContext ctx, ChannelService svc, CancellationToken ct) =>
+        {
+            var req = await ReadJson(ctx.Request, ApiJson.Default.ObjectEnvelope, ct);
+            return Json(svc.DeclareObject(ParseId(id), RequestAuth.FromHeaders(ctx.Request, false), req), ApiJson.Default.ObjectEnvelope, 201);
+        });
+        api.MapPatch("/spaces/{id}/channels/{channelId}/history", async (string id, string channelId, HttpContext ctx, ChannelService svc, CancellationToken ct) =>
+        {
+            var req = await ReadJson(ctx.Request, ApiJson.Default.ChannelHistoryRequest, ct);
+            svc.SetChannelHistory(ParseId(id), RequestAuth.FromHeaders(ctx.Request, false), channelId, req.ChatHistory, req.FilesHistory); return Results.NoContent();
+        });
+    }
+}

server/src/WebDrop.Api/Endpoints/Endpoints.cs

@@ -1,6 +1,8 @@
 using System.Buffers;
 using System.Diagnostics;
+using System.IO.Compression;
 using System.Net.WebSockets;
+using System.Security.Cryptography;
 using System.Text.Json;
 using System.Text.Json.Serialization.Metadata;
 using WebDrop.Core;
@@ -15,7 +17,7 @@ public static partial class Endpoints
     private const string OctetStream = "application/octet-stream";
     private static readonly TimeSpan MaxLongPoll = TimeSpan.FromSeconds(25);
 
-    public static void MapApi(this IEndpointRouteBuilder app, WebDropOptions options, ICaptchaVerifier captcha, SqliteAccountStore accounts)
+    public static void MapApi(this IEndpointRouteBuilder app, WebDropOptions options, ICaptchaVerifier captcha, SqliteAccountStore accounts, IFileGrants files)
     {
         var api = app.MapGroup("/api/v1");
 
@@ -28,17 +30,34 @@ public static partial class Endpoints
                 ApiEndpoint = captcha.Enabled ? options.Captcha.ApiEndpoint : null,
             },
             Transports = new TransportsBody { Http3 = options.EnableHttp3 },
+            Defaults = new DefaultsBody { Channel = CreationDefaults.Channel(limits), Share = CreationDefaults.Share(limits) },
+            Files = new FilesInfoBody { Enabled = files.Enabled, Url = files.Enabled ? files.PublicUrl : null },
+            Choices = new SettingChoicesBody
+            {
+                MaxMembers = new[] { 2, 3, 5, 10, limits.MaxMembers }.Where(n => n >= 1 && n <= limits.MaxMembers).Distinct().Order().ToArray(),
+                TtlSeconds = new[] { 3600, 86_400, 604_800, limits.MinTtlSeconds, limits.MaxTtlSeconds, CreationDefaults.Channel(limits).TtlSeconds }
+                    .Where(n => n >= limits.MinTtlSeconds && n <= limits.MaxTtlSeconds).Distinct().Order().ToArray(),
+                MaxVisitors = new[] { 0, 2, 5, 10, 20, limits.MaxVisitors }.Where(n => n <= limits.MaxVisitors).Distinct().Order().ToArray(),
+            },
             Limits = new LimitsBody
             {
                 MaxPayloadBytes = limits.MaxPayloadBytes,
                 MaxFramesPerItem = limits.MaxFramesPerItem,
                 MaxChannelBytes = limits.MaxChannelBytes,
-                MaxSeats = limits.MaxSeats,
+                MaxWorkspaceBytes = limits.MaxWorkspaceBytes,
+                MaxMembers = limits.MaxMembers,
                 MaxTtlSeconds = limits.MaxTtlSeconds,
+                MinTtlSeconds = limits.MinTtlSeconds,
+                MaxItems = limits.MaxItemsLimit,
+                MaxVisitors = limits.MaxVisitors,
             },
         }, ApiJson.Default.ServerInfoBody));
 
         MapAccounts(api, accounts);
+        MapPasskeys(api, accounts);
+        MapWorkspace(api, accounts);
+        MapWorkspaceCrypto(api);
+        MapFiles(api);
 
         // ───────── 频道 ─────────
 
@@ -46,10 +65,9 @@ public static partial class Endpoints
         {
             if (!TryAccount(ctx, accounts, out var username)) throw new WebDropException(ErrorCode.AccountRequired);
             var req = await ReadJson(ctx.Request, ApiJson.Default.CreateChannelRequest, ct);
-            var endpoint = RequestAuth.ParseEndpointHash(ctx.Request.Headers[RequestAuth.EndpointHeader]);
             string token = ctx.Request.Headers[RequestAuth.CaptchaHeader].ToString();
             await captcha.VerifyAsync(token.Length > 0 ? token : null, ct);
-            return Json(svc.CreateChannel(req, endpoint, username, accounts.SessionDevice(ctx.Request.Headers["X-WD-Account"].ToString())), ApiJson.Default.ChannelInfo, StatusCodes.Status201Created);
+            return Json(svc.CreateChannel(req, username), ApiJson.Default.ChannelInfo, StatusCodes.Status201Created);
         }).RequireRateLimiting(CreatePolicy);
 
         api.MapGet("/channels/{id}", (string id, HttpContext ctx, ChannelService svc) =>
@@ -57,73 +75,54 @@ public static partial class Endpoints
 
         api.MapPatch("/channels/{id}/settings", async (string id, HttpContext ctx, ChannelService svc, CancellationToken ct) =>
         {
-            var patch = await ReadJson(ctx.Request, ApiJson.Default.ChannelSettingsPatch, ct);
+            // 空间头像(动图)比其他设置大得多,单独放宽请求体上限
+            if (ctx.Features.Get<Microsoft.AspNetCore.Http.Features.IHttpMaxRequestBodySizeFeature>() is { IsReadOnly: false } size) size.MaxRequestBodySize = 4 * 1024 * 1024;
+            var patch = await ReadJsonCompressed(ctx.Request, ApiJson.Default.ChannelSettingsPatch, 6 * 1024 * 1024, ct);
             var info = svc.UpdateSettings(ParseId(id), RequestAuth.FromHeaders(ctx.Request, requireEndpoint: false), patch);
             return Json(info, ApiJson.Default.ChannelInfo);
         });
 
+        // 空间头像(信息里只带版本):默认缩略图,size=full 原图。磁盘文件直接发送,带 ETag(内容哈希),没变时回 304
+        api.MapGet("/channels/{id}/avatar", (string id, HttpContext ctx, ChannelService svc) =>
+        {
+            bool thumb = ctx.Request.Query["size"] != "full";
+            return AvatarResult(ctx, svc.GetChannelAvatarBlob(ParseId(id), RequestAuth.FromHeaders(ctx.Request, requireEndpoint: false), thumb));
+        });
+
         api.MapDelete("/channels/{id}", (string id, HttpContext ctx, ChannelService svc) =>
         {
             svc.DeleteChannel(ParseId(id), RequestAuth.FromHeaders(ctx.Request, requireEndpoint: false));
             return Results.NoContent();
         });
 
-        // ───────── 席位 ─────────
+        // ───────── 加入 ─────────
 
-        api.MapPost("/channels/{id}/seats", async (string id, HttpContext ctx, ChannelService svc, CancellationToken ct) =>
+        api.MapPost("/channels/{id}/join", async (string id, HttpContext ctx, ChannelService svc, CancellationToken ct) =>
         {
             var request = ctx.Request.ContentType?.StartsWith("application/json", StringComparison.OrdinalIgnoreCase) == true ? await ReadJson(ctx.Request, ApiJson.Default.JoinRequest, ct) : new JoinRequest();
-            return Json(svc.Join(ParseId(id), RequestAuth.FromHeaders(ctx.Request, requireEndpoint: true), request.Password), ApiJson.Default.SeatJoined);
+            return Json(svc.Join(ParseId(id), RequestAuth.FromHeaders(ctx.Request, requireEndpoint: false), request.Password), ApiJson.Default.JoinResult);
         });
 
         MapChannelAccess(api, accounts);
 
-        api.MapGet("/channels/{id}/seats", (string id, HttpContext ctx, ChannelService svc) =>
-        {
-            var seats = svc.ListSeats(ParseId(id), RequestAuth.FromHeaders(ctx.Request, requireEndpoint: false));
-            return Json([.. seats], ApiJson.Default.ListSeatInfo);
-        });
-
-        api.MapPut("/channels/{id}/seats/me", async (string id, HttpContext ctx, ChannelService svc, ServerLimits limits, CancellationToken ct) =>
-        {
-            var creds = RequestAuth.FromHeaders(ctx.Request, requireEndpoint: true);
-            byte[] label = await ReadBody(ctx.Request, limits.MaxSeatLabelBytes, ct);
-            svc.SetSeatLabel(ParseId(id), creds, label);
-            return Results.NoContent();
-        });
-
-        api.MapPut("/channels/{id}/seats/{endpointHash}/label", async (string id, string endpointHash, HttpContext ctx, ChannelService svc, ServerLimits limits, CancellationToken ct) =>
-        {
-            if (!Codec.TryDecodeExact(endpointHash, TokenHash.Size, out var hash)) throw new WebDropException(ErrorCode.BadRequest);
-            byte[] label = await ReadBody(ctx.Request, limits.MaxSeatLabelBytes, ct);
-            svc.SetSeatLabelForEndpoint(ParseId(id), RequestAuth.FromHeaders(ctx.Request, requireEndpoint: false), hash, label);
-            return Results.NoContent();
-        });
-
-        api.MapDelete("/channels/{id}/seats/{endpointHash}", (string id, string endpointHash, HttpContext ctx, ChannelService svc) =>
-        {
-            if (!Codec.TryDecodeExact(endpointHash, TokenHash.Size, out var hash)) throw new WebDropException(ErrorCode.BadRequest);
-            svc.ReleaseSeat(ParseId(id), RequestAuth.FromHeaders(ctx.Request, requireEndpoint: false), hash);
-            return Results.NoContent();
-        });
-
         // ───────── 帧与日志 ─────────
 
-        api.MapPost("/channels/{id}/frames", async (string id, HttpContext ctx, ChannelService svc, ServerLimits limits, CancellationToken ct) =>
+        api.MapPost("/channels/{id}/frames", async (string id, HttpContext ctx, ChannelService svc, SqliteAccountStore accountStore, ServerLimits limits, CancellationToken ct) =>
         {
             var channelId = ParseId(id);
-            var creds = RequestAuth.FromHeaders(ctx.Request, requireEndpoint: true);
+            var creds = RequestAuth.FromHeaders(ctx.Request, requireEndpoint: false);
             long? maxDownloads = ParseMaxDownloads(ctx.Request.Headers["X-WD-Max-Downloads"].ToString());
 
             byte[] body = await ReadBody(ctx.Request, Envelope.HeaderSize + limits.MaxPayloadBytes, ct);
-            var result = await svc.AppendFrameAsync(channelId, creds, body, maxDownloads, ct);
+            var signedEvent = ParseSignedContentEvent(ctx.Request, accountStore, channelId, creds, body);
+            var result = await svc.AppendFrameAsync(channelId, creds, body, maxDownloads, ct, signedEvent);
             return Json(result, ApiJson.Default.AppendResult, result.Created ? StatusCodes.Status201Created : StatusCodes.Status200OK);
         });
 
         api.MapGet("/channels/{id}/log", async (string id, HttpContext ctx, ChannelService svc, ChannelHub hub, CancellationToken ct) =>
         {
             var channelId = ParseId(id);
-            var creds = RequestAuth.FromHeaders(ctx.Request, requireEndpoint: true);
+            var creds = RequestAuth.FromHeaders(ctx.Request, requireEndpoint: false);
             long from = QueryLong(ctx.Request, "from", 0);
             int limit = (int)Math.Clamp(QueryLong(ctx.Request, "limit", 200), 1, 1000);
             var wait = TimeSpan.FromSeconds(Math.Clamp(QueryLong(ctx.Request, "wait", 0), 0, 25));
@@ -171,7 +170,7 @@ public static partial class Endpoints
         api.MapGet("/channels/{id}/events", async (string id, HttpContext ctx, ChannelService svc, ChannelHub hub) =>
         {
             var channelId = ParseId(id);
-            var creds = RequestAuth.FromHeaders(ctx.Request, requireEndpoint: true);
+            var creds = RequestAuth.FromHeaders(ctx.Request, requireEndpoint: false);
             long from = QueryLong(ctx.Request, "from", -1);
             if (from < 0)
                 from = long.TryParse(ctx.Request.Headers["Last-Event-ID"].ToString(), out long last) && last >= 0 ? last + 1 : 0;
@@ -192,7 +191,7 @@ public static partial class Endpoints
         {
             var channelId = ParseId(id);
             var item = ParseId(itemId);
-            var creds = RequestAuth.FromHeaders(ctx.Request, requireEndpoint: true);
+            var creds = RequestAuth.FromHeaders(ctx.Request, requireEndpoint: false);
             long from = QueryLong(ctx.Request, "from", 0);
             if (from is < 0 or > uint.MaxValue) throw new WebDropException(ErrorCode.BadRequest);
 
@@ -217,9 +216,12 @@ public static partial class Endpoints
             return Results.Empty;
         });
 
-        api.MapDelete("/channels/{id}/items/{itemId}", (string id, string itemId, HttpContext ctx, ChannelService svc) =>
+        api.MapDelete("/channels/{id}/items/{itemId}", (string id, string itemId, HttpContext ctx, ChannelService svc, SqliteAccountStore accountStore) =>
         {
-            svc.DeleteItem(ParseId(id), RequestAuth.FromHeaders(ctx.Request, requireEndpoint: true), ParseId(itemId));
+            var channelId = ParseId(id); var parsedItemId = ParseId(itemId);
+            var creds = RequestAuth.FromHeaders(ctx.Request, requireEndpoint: false);
+            var proof = ParseSignedDeleteEvent(ctx.Request, accountStore, svc, channelId, parsedItemId, creds);
+            svc.DeleteItem(channelId, creds, parsedItemId, proof);
             return Results.NoContent();
         });
 
@@ -355,6 +357,85 @@ public static partial class Endpoints
         catch (Exception e) when (e is JsonException or KeyNotFoundException or InvalidOperationException) { throw new WebDropException(ErrorCode.BadRequest); }
     }
 
+    private static SignedContentEventProof? ParseSignedContentEvent(HttpRequest request, SqliteAccountStore accounts,
+        Id16 spaceId, Credentials creds, byte[] frame)
+    {
+        string[] names = ["X-WD-Event-Id", "X-WD-Event-Kind", "X-WD-Event-Channel", "X-WD-Event-Domain",
+            "X-WD-Event-Epoch", "X-WD-Event-Frames", "X-WD-Event-Manifest", "X-WD-Event-Signature", "X-WD-Event-Target"];
+        var values = names.Select(name => request.Headers[name].ToString()).ToArray();
+        bool any = values.Any(value => value.Length > 0);
+        if (!any)
+        {
+            if ((Envelope.TryParse(frame, out var legacyEnvelope) || Envelope.TryParseHeader(frame, out legacyEnvelope)) && legacyEnvelope.IsFinal && creds.AccountName is not null
+                && creds.AccountDeviceId is not null && accounts.DeviceSigningKey(creds.AccountName, creds.AccountDeviceId) is not null)
+                throw new WebDropException(ErrorCode.Forbidden);
+            return null;
+        }
+        if (!(Envelope.TryParse(frame, out var envelope) || Envelope.TryParseHeader(frame, out envelope)) || !envelope.IsFinal || creds.AccountName is null || creds.AccountDeviceId is null
+            || values.Take(8).Any(string.IsNullOrEmpty)) throw new WebDropException(ErrorCode.BadRequest);
+        if (!Guid.TryParseExact(values[2], "D", out _) || values[3] is not ("chat" or "files")
+            || !int.TryParse(values[4], out var epoch) || epoch < 0
+            || !int.TryParse(values[5], out var frameCount) || frameCount < 1 || frameCount > 65_536)
+            throw new WebDropException(ErrorCode.BadRequest);
+        var domain = values[3] == "chat" ? CryptoDomain.Chat : CryptoDomain.Files;
+        var eventKind = values[1];
+        if (domain == CryptoDomain.Chat && !eventKind.StartsWith("chat.", StringComparison.Ordinal)
+            || domain == CryptoDomain.Files && !eventKind.StartsWith("file.", StringComparison.Ordinal)) throw new WebDropException(ErrorCode.BadRequest);
+        if (!Codec.TryDecodeExact(values[0], 16, out var eventId)
+            || !Codec.TryDecodeExact(values[6], 32, out var manifestHash)
+            || !Codec.TryDecodeExact(values[7], 64, out var signature)) throw new WebDropException(ErrorCode.BadRequest);
+        byte[] target = [];
+        if (values[8].Length > 0 && !Codec.TryDecodeExact(values[8], 16, out target)) throw new WebDropException(ErrorCode.BadRequest);
+
+        var deviceKey = accounts.DeviceSigningKey(creds.AccountName, creds.AccountDeviceId)
+            ?? throw new WebDropException(ErrorCode.Forbidden);
+        var rootPublicKey = accounts.GetSigningPublicKey(creds.AccountName) ?? throw new WebDropException(ErrorCode.Forbidden);
+        using var publicKey = JsonDocument.Parse(deviceKey.PublicKey);
+        var jwk = publicKey.RootElement;
+        if (!Codec.TryDecodeExact(jwk.GetProperty("x").GetString(), 32, out var x)
+            || !Codec.TryDecodeExact(jwk.GetProperty("y").GetString(), 32, out var y)) throw new WebDropException(ErrorCode.BadRequest);
+        var payload = SignatureCodec.ContentEventPayload(spaceId.ToArray(), values[2], creds.AccountName,
+            creds.AccountDeviceId, eventId, eventKind, domain, epoch, envelope.ItemId.ToArray(), frameCount, manifestHash, target);
+        if (!SignatureCodec.VerifyP256(x, y, "content.event", payload, signature)) throw new WebDropException(ErrorCode.Forbidden);
+        return new SignedContentEventProof(eventId, eventKind, creds.AccountName, values[2], domain, epoch, frameCount,
+            manifestHash, creds.AccountDeviceId, signature, values[8].Length == 0 ? null : values[8],
+            rootPublicKey, deviceKey.PublicKey, deviceKey.CertificateSignature);
+    }
+
+    private static SignedContentEventProof? ParseSignedDeleteEvent(HttpRequest request, SqliteAccountStore accounts,
+        ChannelService service, Id16 spaceId, Id16 itemId, Credentials creds)
+    {
+        string[] names = ["X-WD-Event-Id", "X-WD-Event-Kind", "X-WD-Event-Channel", "X-WD-Event-Domain",
+            "X-WD-Event-Epoch", "X-WD-Event-Frames", "X-WD-Event-Manifest", "X-WD-Event-Signature"];
+        var values = names.Select(name => request.Headers[name].ToString()).ToArray();
+        if (values.All(string.IsNullOrEmpty)) return null;
+        if (creds.AccountName is null || creds.AccountDeviceId is null || values.Any(string.IsNullOrEmpty)) throw new WebDropException(ErrorCode.BadRequest);
+        var obj = service.ObjectSigningContext(spaceId, creds, itemId) ?? throw new WebDropException(ErrorCode.NotFound);
+        var createdEvent = obj.Event ?? throw new WebDropException(ErrorCode.BadRequest);
+        if (!Guid.TryParseExact(values[2], "D", out _) || values[3] is not ("chat" or "files")
+            || !int.TryParse(values[4], out var epoch) || !int.TryParse(values[5], out var frameCount)) throw new WebDropException(ErrorCode.BadRequest);
+        var domain = values[3] == "chat" ? CryptoDomain.Chat : CryptoDomain.Files;
+        var kind = domain == CryptoDomain.Chat ? "chat.delete" : "file.delete";
+        if (values[1] != kind || obj.ChannelId != values[2] || obj.Domain != domain || obj.Epoch != epoch
+            || createdEvent.FrameCount != frameCount
+            || !Codec.TryDecodeExact(values[0], 16, out var eventId)
+            || !Codec.TryDecodeExact(values[6], 32, out var manifest)
+            || !Codec.TryDecodeExact(values[7], 64, out var signature)
+            || !Codec.TryDecodeExact(createdEvent.ManifestHash, 32, out var objectManifest)
+            || !CryptographicOperations.FixedTimeEquals(manifest, objectManifest)) throw new WebDropException(ErrorCode.BadRequest);
+
+        var deviceKey = accounts.DeviceSigningKey(creds.AccountName, creds.AccountDeviceId) ?? throw new WebDropException(ErrorCode.Forbidden);
+        using var publicKey = JsonDocument.Parse(deviceKey.PublicKey); var jwk = publicKey.RootElement;
+        if (!Codec.TryDecodeExact(jwk.GetProperty("x").GetString(), 32, out var x)
+            || !Codec.TryDecodeExact(jwk.GetProperty("y").GetString(), 32, out var y)) throw new WebDropException(ErrorCode.BadRequest);
+        var payload = SignatureCodec.ContentEventPayload(spaceId.ToArray(), obj.ChannelId, creds.AccountName,
+            creds.AccountDeviceId, eventId, kind, domain, epoch, itemId.ToArray(), frameCount, manifest, []);
+        if (!SignatureCodec.VerifyP256(x, y, "content.event", payload, signature)) throw new WebDropException(ErrorCode.Forbidden);
+        return new SignedContentEventProof(eventId, kind, creds.AccountName, obj.ChannelId, domain, epoch, frameCount,
+            manifest, creds.AccountDeviceId, signature, null, accounts.GetSigningPublicKey(creds.AccountName)!,
+            deviceKey.PublicKey, deviceKey.CertificateSignature);
+    }
+
     private static byte[] DecodeBase64(string? value, int minLength, int maxLength)
     {
         if (value is null || value.Length > ((maxLength + 2) / 3 * 4)) throw new WebDropException(ErrorCode.BadRequest);
@@ -382,6 +463,40 @@ public static partial class Endpoints
         return long.TryParse(header, out long n) && n >= 0 ? n : throw new WebDropException(ErrorCode.BadRequest);
     }
 
+    /// <summary>
+    /// 读 JSON 请求体,支持 Content-Encoding: gzip(头像这类带 base64 的大请求,压缩后能省下 base64 多出来的约四分之一)。
+    /// 解压后的大小另外限制,防止小体积的压缩炸弹。
+    /// </summary>
+    private static async Task<T> ReadJsonCompressed<T>(HttpRequest req, JsonTypeInfo<T> info, int maxBytes, CancellationToken ct) where T : class
+    {
+        try
+        {
+            Stream body = req.Body;
+            if (string.Equals(req.Headers.ContentEncoding.ToString(), "gzip", StringComparison.OrdinalIgnoreCase)) body = new GZipStream(req.Body, CompressionMode.Decompress);
+            using var plain = new MemoryStream();
+            var buffer = new byte[81920]; int read;
+            while ((read = await body.ReadAsync(buffer, ct)) > 0)
+            {
+                if (plain.Length + read > maxBytes) throw new WebDropException(ErrorCode.BadRequest);
+                plain.Write(buffer, 0, read);
+            }
+            plain.Position = 0;
+            return await JsonSerializer.DeserializeAsync(plain, info, ct) ?? throw new WebDropException(ErrorCode.BadRequest);
+        }
+        catch (Exception error) when (error is JsonException or InvalidDataException) { throw new WebDropException(ErrorCode.BadRequest); }
+    }
+
+    /// <summary>头像文件(带 ETag = 内容哈希,没变时 304)。直接按路径发送,不读进内存</summary>
+    private static IResult AvatarResult(HttpContext ctx, AvatarBlob? blob)
+    {
+        if (blob is null) return Results.NotFound();
+        var etag = $"\"{blob.Hash}\"";
+        ctx.Response.Headers.ETag = etag;
+        ctx.Response.Headers.CacheControl = "private, no-cache";
+        if (ctx.Request.Headers.IfNoneMatch == etag) return Results.StatusCode(StatusCodes.Status304NotModified);
+        return Results.File(blob.Path, blob.Mime);
+    }
+
     private static async Task<T> ReadJson<T>(HttpRequest req, JsonTypeInfo<T> info, CancellationToken ct) where T : class
     {
         try
@@ -399,7 +514,21 @@ public static partial class Endpoints
     {
         if (req.ContentLength is { } declared && declared > max) throw new WebDropException(ErrorCode.TooLarge);
 
-        using var ms = new MemoryStream(req.ContentLength is { } len ? (int)len : 1024);
+        // 长度已知:直接读进刚好大小的数组,少一份拷贝(帧最大几 MB,多一份就是一次大对象分配)
+        if (req.ContentLength is { } known)
+        {
+            var exact = new byte[(int)known];
+            int filled = 0;
+            while (filled < exact.Length)
+            {
+                int got = await req.Body.ReadAsync(exact.AsMemory(filled), ct);
+                if (got == 0) throw new WebDropException(ErrorCode.BadRequest);
+                filled += got;
+            }
+            return exact;
+        }
+
+        using var ms = new MemoryStream(1024);
         byte[] buffer = ArrayPool<byte>.Shared.Rent(16 * 1024);
         try
         {

server/src/WebDrop.Api/Files/FileGrants.cs

@@ -0,0 +1,24 @@
+using System.Text;
+using WebDrop.Core;
+using WebDrop.FileProtocol;
+
+namespace WebDrop.Api;
+
+/// <summary>
+/// 主后端这一侧和文件服务的全部关系:拿共用的密钥给客户端签短期票据。
+/// 它不调用文件服务、不保存文件服务的任何状态;文件域怎么创建、多大、用了多少,都是客户端直接和文件服务之间的事。
+/// </summary>
+public sealed class FileGrants(FileApiOptions options) : IFileGrants
+{
+    private readonly byte[] _secret = Encoding.UTF8.GetBytes(options.Secret);
+    private readonly string _publicUrl = options.PublicUrl.TrimEnd('/');
+
+    public bool Enabled => true;
+    public string PublicUrl => _publicUrl;
+
+    public FileGrant Issue(FileOp op, string space, string scope, string item, uint from, long nowMs)
+    {
+        long expires = nowMs + Math.Max(30, options.TicketSeconds) * 1000L;
+        return new FileGrant(_publicUrl, op == FileOp.Create ? "" : scope, FileTokens.Sign(_secret, new FileTicket(op, scope, item, from, expires, space)), expires);
+    }
+}

server/src/WebDrop.Api/Hosting/ApiContract.cs

@@ -0,0 +1,10 @@
+namespace WebDrop.Api;
+
+public static class ApiContract
+{
+    // v5: 频道容量按账号成员计;v7: seats 改名 max_members/members_used/members_full,
+    // 去掉设备名与设备清单接口。设备只是账号的属性。
+    // v8: 频道强制登录,去掉未登录访客(allow_guests、/guests、终端席位);便捷分享不受影响。
+    // Keep this aligned with contracts/api-contract.json and docs/openapi.yaml.
+    public const string Version = "8.2.0";
+}

server/src/WebDrop.Api/Hosting/BackupWorker.cs

@@ -0,0 +1,79 @@
+using System.IO.Compression;
+using System.Globalization;
+using WebDrop.Storage;
+using WebDrop.Sync;
+
+namespace WebDrop.Api;
+
+/// <summary>
+/// 每天把数据库快照(聊天、头像、账号)压缩后上传到外部存储,只在本地留一个临时文件。
+/// 外部存储里按日期留 RetainDays 份:用户删掉的聊天,最多再在备份里留这么久。
+/// </summary>
+public sealed class BackupWorker(WebDropOptions options, SqliteChannelStore store, ILogger<BackupWorker> logger) : BackgroundService
+{
+    private readonly HttpClient _http = new() { Timeout = TimeSpan.FromMinutes(30) };
+    private const string Prefix = "webdrop-";
+
+    protected override async Task ExecuteAsync(CancellationToken stoppingToken)
+    {
+        var backup = options.Backup;
+        if (!backup.Enabled || !backup.S3.Configured) return;
+        while (!stoppingToken.IsCancellationRequested)
+        {
+            try { await Task.Delay(DailySchedule.Next(DateTime.Now, backup.TimeOfDay) - DateTime.Now, stoppingToken).ConfigureAwait(false); } catch (OperationCanceledException) { break; }
+            try { await RunOnceAsync(DateTime.Now, stoppingToken).ConfigureAwait(false); }
+            catch (OperationCanceledException) when (stoppingToken.IsCancellationRequested) { break; }
+            catch (Exception e) { logger.LogWarning("数据库备份失败:{Type}", e.GetType().Name); }
+        }
+    }
+
+    public async Task<(string Name, int Purged)> RunOnceAsync(DateTime now, CancellationToken ct)
+    {
+        var backup = options.Backup;
+        var s3 = new S3Client(_http, backup.S3);
+        string tmp = Path.Combine(options.DataDir, "v2", "backup-tmp");
+        Directory.CreateDirectory(tmp);
+        string name = $"{Prefix}{now:yyyyMMdd-HHmm}.db.gz";
+        string db = Path.Combine(tmp, $"snapshot-{Guid.NewGuid():N}.db"), gz = db + ".gz";
+        try
+        {
+            store.Snapshot(db);
+            await using (var source = File.OpenRead(db))
+            await using (var target = File.Create(gz))
+            await using (var zip = new GZipStream(target, CompressionLevel.SmallestSize))
+                await source.CopyToAsync(zip, ct).ConfigureAwait(false);
+            await using (var upload = File.OpenRead(gz))
+                await s3.PutAsync($"chat/{name}", upload, ct).ConfigureAwait(false);
+        }
+        finally
+        {
+            foreach (var path in new[] { db, gz }) try { File.Delete(path); } catch (IOException) { }
+        }
+
+        // 头像是按内容哈希命名的磁盘文件(不在数据库里):内容不会变,已经上传过的跳过
+        foreach (var kind in new[] { "space", "account" })
+        {
+            string directory = Path.Combine(options.DataDir, "v2", "avatars", kind);
+            if (!Directory.Exists(directory)) continue;
+            var uploaded = (await s3.ListAsync($"chat/avatars/{kind}", ct).ConfigureAwait(false)).ToHashSet();
+            foreach (var file in Directory.EnumerateFiles(directory))
+            {
+                if (file.EndsWith(".tmp", StringComparison.Ordinal) || uploaded.Contains(Path.GetFileName(file))) continue;
+                await using var content = File.OpenRead(file);
+                await s3.PutAsync($"chat/avatars/{kind}/{Path.GetFileName(file)}", content, ct).ConfigureAwait(false);
+            }
+        }
+
+        // 保留期:按文件名里的日期清理更早的
+        int purged = 0;
+        var cutoff = now.Date.AddDays(-Math.Max(0, backup.RetainDays));
+        foreach (var existing in await s3.ListAsync("chat", ct).ConfigureAwait(false))
+        {
+            if (!existing.StartsWith(Prefix, StringComparison.Ordinal) || existing.Length < Prefix.Length + 8) continue;
+            if (!DateTime.TryParseExact(existing.AsSpan(Prefix.Length, 8), "yyyyMMdd", CultureInfo.InvariantCulture, DateTimeStyles.None, out var date) || date >= cutoff) continue;
+            if (await s3.DeleteAsync($"chat/{existing}", ct).ConfigureAwait(false)) purged++;
+        }
+        if (purged > 0) logger.LogInformation("清理了 {Count} 份过期的数据库备份", purged);
+        return (name, purged);
+    }
+}

server/src/WebDrop.Api/Hosting/CapCaptchaVerifier.cs

@@ -16,6 +16,11 @@ public sealed class SiteverifyResponse
     [JsonPropertyName("success")] public bool Success { get; init; }
 }
 
+// Backend-to-Cap DTOs are not part of the browser API contract.
+[JsonSerializable(typeof(SiteverifyRequest))]
+[JsonSerializable(typeof(SiteverifyResponse))]
+public sealed partial class CaptchaJson : JsonSerializerContext;
+
 /// <summary>
 /// 用 Cap(https://github.com/tiagozip/cap)校验创建频道的验证码。
 /// 工作量证明的出题、求解、验证全部由 Cap 完成,本项目不实现任何 PoW。
@@ -36,7 +41,7 @@ public sealed class CapCaptchaVerifier(HttpClient http, CaptchaOptions options,
             throw new WebDropException(ErrorCode.CaptchaRequired);
 
         var body = JsonSerializer.Serialize(
-            new SiteverifyRequest { Secret = options.Secret, Response = token }, ApiJson.Default.SiteverifyRequest);
+            new SiteverifyRequest { Secret = options.Secret, Response = token }, CaptchaJson.Default.SiteverifyRequest);
 
         try
         {
@@ -55,7 +60,7 @@ public sealed class CapCaptchaVerifier(HttpClient http, CaptchaOptions options,
 
             var result = await JsonSerializer.DeserializeAsync(
                 await response.Content.ReadAsStreamAsync(ct).ConfigureAwait(false),
-                ApiJson.Default.SiteverifyResponse, ct).ConfigureAwait(false);
+                CaptchaJson.Default.SiteverifyResponse, ct).ConfigureAwait(false);
 
             if (result is not { Success: true }) throw new WebDropException(ErrorCode.CaptchaRequired);
         }

server/src/WebDrop.Api/Hosting/RequestAuth.cs

@@ -35,7 +35,8 @@ public static class RequestAuth
             deviceId = accounts.SessionDevice(accountToken);
         }
         if (role == Role.Owner && accountName is null) throw new WebDropException(ErrorCode.AccountRequired);
-        return new Credentials(role, token, ParseEndpoint(req.Headers[EndpointHeader].ToString(), requireEndpoint), accountName, deviceId);
+        // 账号以会话鉴权;终端密钥只用于便捷分享(未登录的创建者与读者)
+        return new Credentials(role, token, ParseEndpoint(req.Headers[EndpointHeader].ToString(), requireEndpoint && accountName is null), accountName, deviceId, accountName is not null);
     }
 
     /// <summary>
@@ -68,7 +69,7 @@ public static class RequestAuth
         }
         var parsedRole = ParseRole(role);
         if (parsedRole == Role.Owner && accountName is null) throw new WebDropException(ErrorCode.AccountRequired);
-        return new Credentials(parsedRole, token, ParseEndpoint(endpoint, requireEndpoint: true), accountName, deviceId);
+        return new Credentials(parsedRole, token, ParseEndpoint(endpoint, requireEndpoint: false), accountName, deviceId, accountName is not null);
     }
 
     public static byte[] ParseEndpointHash(string? header) => ParseEndpoint(header, requireEndpoint: true);

server/src/WebDrop.Api/Hosting/WebDropApp.cs

@@ -1,4 +1,6 @@
 using System.Threading.RateLimiting;
+using Microsoft.AspNetCore.Identity;
+using Microsoft.Extensions.Options;
 using WebDrop.Core;
 using WebDrop.Frontend;
 using WebDrop.Storage;
@@ -27,15 +29,42 @@ public static class WebDropApp
         builder.Services.AddSingleton<IBlobStore>(_ => new DiskBlobStore(Path.Combine(options.DataDir, "v2", "blobs")));
         builder.Services.AddSingleton<SqliteChannelStore>(_ => new SqliteChannelStore(Path.Combine(options.DataDir, "v2", "webdrop.db")));
         builder.Services.AddSingleton<SqliteAccountStore>(_ => new SqliteAccountStore(Path.Combine(options.DataDir, "v2", "webdrop.db")));
+        builder.Services.AddSingleton<PasskeyCeremonies>();
+        builder.Services.AddScoped<PasskeyUserStore>();
+        builder.Services.AddScoped<UserManager<PasskeyAccount>>(sp => new(
+            sp.GetRequiredService<PasskeyUserStore>(), Options.Create(new IdentityOptions()), new PasswordHasher<PasskeyAccount>(), [], [],
+            new UpperInvariantLookupNormalizer(), new IdentityErrorDescriber(), sp, sp.GetRequiredService<ILogger<UserManager<PasskeyAccount>>>()));
+        builder.Services.Configure<IdentityPasskeyOptions>(o =>
+        {
+            o.ServerDomain = options.PasskeyRpId;
+            o.UserVerificationRequirement = "required"; o.ResidentKeyRequirement = "required";
+            o.AttestationConveyancePreference = "none"; o.AuthenticatorTimeout = TimeSpan.FromMinutes(2);
+            o.IsAllowedAlgorithm = algorithm => algorithm == -7;
+            o.ValidateOrigin = context => ValueTask.FromResult(!context.CrossOrigin && context.TopOrigin is null
+                && Uri.TryCreate(context.Origin, UriKind.Absolute, out var origin)
+                && (options.CorsOrigins.Contains(origin.GetLeftPart(UriPartial.Authority), StringComparer.Ordinal)
+                    || origin.GetLeftPart(UriPartial.Authority) == $"{context.HttpContext.Request.Scheme}://{context.HttpContext.Request.Host}"));
+        });
+        builder.Services.AddScoped<IPasskeyHandler<PasskeyAccount>, PasskeyHandler<PasskeyAccount>>();
         builder.Services.AddSingleton<IResourceStore>(sp => sp.GetRequiredService<SqliteChannelStore>());
         builder.Services.AddSingleton<ICaptchaVerifier>(sp => CreateCaptchaVerifier(options.Captcha, sp));
         builder.Services.AddSingleton<ChannelHub>();
         builder.Services.AddSingleton<IChannelEvents>(sp => sp.GetRequiredService<ChannelHub>());
-        builder.Services.AddSingleton<ChannelService>();
+        options.Files.Validate();
+        builder.Services.AddSingleton<IFileGrants>(_ => options.Files.Enabled ? new FileGrants(options.Files) : NoFileGrants.Instance);
+        builder.Services.AddSingleton<BackupWorker>();
+        builder.Services.AddHostedService(sp => sp.GetRequiredService<BackupWorker>());
+        builder.Services.AddSingleton<ChannelService>(sp => new ChannelService(
+            sp.GetRequiredService<IResourceStore>(),
+            sp.GetRequiredService<IBlobStore>(),
+            sp.GetRequiredService<IClock>(), options.Limits, sp.GetRequiredService<IChannelEvents>(), sp.GetRequiredService<IFileGrants>()));
         builder.Services.AddSingleton<ShareService>(sp => new ShareService(
             sp.GetRequiredService<IResourceStore>(), sp.GetRequiredService<IBlobStore>(), sp.GetRequiredService<IClock>(),
             options.Limits, options.ShareDraftTtlSeconds));
         builder.Services.AddHostedService<SweepWorker>();
+        // JSON(如 crypto 状态)与前端静态资源压缩后再传;认证走请求头而非 cookie,开启 HTTPS 压缩不会带来 BREACH 风险。
+        // 默认 MIME 列表不含 text/event-stream 与 octet-stream,日志流和密文不受影响
+        builder.Services.AddResponseCompression(o => o.EnableForHttps = true);
 
         if (options.CorsOrigins.Length > 0)
         {
@@ -43,8 +72,10 @@ public static class WebDropApp
                 .WithOrigins(options.CorsOrigins)
                 .AllowAnyMethod()
                 .WithHeaders("Authorization", "Content-Type", "Last-Event-ID",
-                    "X-WD-Role", "X-WD-Endpoint", "X-WD-Cap", "X-WD-Max-Downloads", "X-WD-Account")
-                .WithExposedHeaders("X-WD-Last-Seq")
+                    "X-WD-Role", "X-WD-Endpoint", "X-WD-Cap", "X-WD-Max-Downloads", "X-WD-Account",
+                    "X-WD-Event-Id", "X-WD-Event-Kind", "X-WD-Event-Channel", "X-WD-Event-Domain",
+                    "X-WD-Event-Epoch", "X-WD-Event-Frames", "X-WD-Event-Manifest", "X-WD-Event-Signature", "X-WD-Event-Target", "X-WD-Receipt")
+                .WithExposedHeaders("X-WD-Last-Seq", "Retry-After")
                 .SetPreflightMaxAge(TimeSpan.FromHours(1))));
         }
 
@@ -52,13 +83,17 @@ public static class WebDropApp
         {
             r.RejectionStatusCode = StatusCodes.Status429TooManyRequests;
             // 限流状态只在内存里,按 IP 分区,不落盘
-            r.GlobalLimiter = PartitionedRateLimiter.Create<HttpContext, string>(ctx =>
-                RateLimitPartition.GetFixedWindowLimiter(ClientKey(ctx), _ => PerMinute(options.RequestsPerMinute)));
+            r.GlobalLimiter = PartitionedRateLimiter.Create<HttpContext, string>(ctx => IsFrameUpload(ctx.Request)
+                ? RateLimitPartition.GetFixedWindowLimiter("frames:" + ClientKey(ctx), _ => PerMinute(options.FrameRequestsPerMinute))
+                : RateLimitPartition.GetFixedWindowLimiter(ClientKey(ctx), _ => PerMinute(options.RequestsPerMinute)));
             r.AddPolicy(Endpoints.CreatePolicy, ctx =>
                 RateLimitPartition.GetFixedWindowLimiter(ClientKey(ctx), _ => PerMinute(options.ChannelCreatesPerMinute)));
             r.OnRejected = async (context, ct) =>
             {
                 context.HttpContext.Response.StatusCode = StatusCodes.Status429TooManyRequests;
+                // 告诉客户端多久后窗口重置,弱网和上传重试据此等待,不再盲目重试
+                if (context.Lease.TryGetMetadata(MetadataName.RetryAfter, out var retryAfter))
+                    context.HttpContext.Response.Headers.RetryAfter = Math.Max(1, (int)Math.Ceiling(retryAfter.TotalSeconds)).ToString(System.Globalization.CultureInfo.InvariantCulture);
                 await context.HttpContext.Response.WriteAsJsonAsync(
                     new ErrorBody { Error = ErrorCode.RateLimited.ToWire() }, ApiJson.Default.ErrorBody, cancellationToken: ct);
             };
@@ -78,13 +113,14 @@ public static class WebDropApp
             });
         }
 
+        app.UseResponseCompression();
         app.Use(SecurityHeaders);
         app.Use(HandleErrors);
         if (options.CorsOrigins.Length > 0) app.UseCors();
         app.UseWebSockets(new WebSocketOptions { KeepAliveInterval = LogStreamer.Heartbeat });
         app.UseRateLimiter();
         EmbeddedFrontend.Use(app, options.Captcha.ApiEndpoint);
-        app.MapApi(options, app.Services.GetRequiredService<ICaptchaVerifier>(), app.Services.GetRequiredService<SqliteAccountStore>());
+        app.MapApi(options, app.Services.GetRequiredService<ICaptchaVerifier>(), app.Services.GetRequiredService<SqliteAccountStore>(), app.Services.GetRequiredService<IFileGrants>());
         return app;
     }
 
@@ -109,6 +145,9 @@ public static class WebDropApp
         }
     }
 
+    private static bool IsFrameUpload(HttpRequest request) =>
+        HttpMethods.IsPost(request.Method) && request.Path.Value is { } path && path.EndsWith("/frames", StringComparison.Ordinal);
+
     private static string ClientKey(HttpContext ctx) => ctx.Connection.RemoteIpAddress?.ToString() ?? "unknown";
 
     private static FixedWindowRateLimiterOptions PerMinute(int permits) => new()

server/src/WebDrop.Api/Hosting/WebDropOptions.cs

@@ -1,4 +1,5 @@
 using WebDrop.Core;
+using WebDrop.Sync;
 
 namespace WebDrop.Api;
 
@@ -18,8 +19,14 @@ public sealed class WebDropOptions
     /// 服务端进程本身不内置 QUIC:CreateSlimBuilder 不含 HTTP/3,需要时再接入。
     /// </summary>
     public bool EnableHttp3 { get; set; }
+    public string? PasskeyRpId { get; set; }
 
     public int RequestsPerMinute { get; set; } = 600;
+    /// <summary>
+    /// 上传帧(POST .../frames)单独计数。每帧最多约 1 MiB,和普通 API 请求放在一个 600/分钟的桶里,
+    /// 持续上传速度就被锁在约 10 MiB/s;帧的总量另有空间配额和单条上限保护。
+    /// </summary>
+    public int FrameRequestsPerMinute { get; set; } = 6000;
     public int ChannelCreatesPerMinute { get; set; } = 30;
     public int ShareDraftTtlSeconds { get; set; } = 86_400;
     public int SweepIntervalSeconds { get; set; } = 30;
@@ -27,6 +34,38 @@ public sealed class WebDropOptions
     public ServerLimits Limits { get; set; } = new();
 
     public CaptchaOptions Captcha { get; set; } = new();
+
+    /// <summary>文件服务(fileAPI)。关闭时文件帧仍存在本进程的存储里。</summary>
+    public FileApiOptions Files { get; set; } = new();
+
+    /// <summary>每天把数据库(聊天、头像、账号)做个快照,压缩后上传到外部存储(S3 协议),保留 RetainDays 天</summary>
+    public DailyBackupOptions Backup { get; set; } = new() { Time = "04:15" };
+}
+
+/// <summary>
+/// 文件的内容不放主后端,由另一台机器上的文件服务(fileAPI)保存。主后端只保存聊天、头像、空间结构和文件的元数据与摘要,
+/// 并按空间里的权限给客户端签发访问文件服务的短期票据;客户端直接和文件服务通信,主后端不调用它。
+/// </summary>
+public sealed class FileApiOptions
+{
+    public bool Enabled { get; set; }
+
+    /// <summary>浏览器访问文件服务的地址(经反向隧道对外的那个),形如 https://files.example.com</summary>
+    public string PublicUrl { get; set; } = "";
+
+    /// <summary>和文件服务共用的密钥,至少 32 个字符。用来给票据签名</summary>
+    public string Secret { get; set; } = "";
+
+    public int TicketSeconds { get; set; } = 600;
+
+
+    public string Validate()
+    {
+        if (!Enabled) return "";
+        if (!Uri.TryCreate(PublicUrl, UriKind.Absolute, out var pub) || pub.Scheme is not ("http" or "https")) throw new InvalidOperationException("WebDrop:Files:PublicUrl 必须是 http(s) 绝对地址");
+        if (Secret.Length < 32) throw new InvalidOperationException("WebDrop:Files:Secret 至少 32 个字符");
+        return pub.GetLeftPart(UriPartial.Authority).TrimEnd('/');
+    }
 }
 
 /// <summary>

server/src/WebDrop.Api/Json/ApiJson.cs

@@ -0,0 +1,323 @@
+using System.Text.Json.Serialization;
+using WebDrop.Core;
+
+namespace WebDrop.Api;
+
+public sealed class ErrorBody
+{
+    [JsonPropertyName("error")] public required string Error { get; init; }
+}
+
+public sealed class GoneLogBody
+{
+    [JsonPropertyName("error")] public string Error { get; init; } = "gone";
+    [JsonPropertyName("oldest_seq")] public required long OldestSeq { get; init; }
+}
+
+public sealed class ServerInfoBody
+{
+    [JsonPropertyName("protocol")] public int Protocol { get; init; } = 1;
+    [JsonPropertyName("contract_version")] public string ContractVersion { get; init; } = ApiContract.Version;
+    [JsonPropertyName("captcha")] public required CaptchaBody Captcha { get; init; }
+    [JsonPropertyName("transports")] public required TransportsBody Transports { get; init; }
+    [JsonPropertyName("limits")] public required LimitsBody Limits { get; init; }
+    [JsonPropertyName("defaults")] public required DefaultsBody Defaults { get; init; }
+    [JsonPropertyName("choices")] public required SettingChoicesBody Choices { get; init; }
+    [JsonPropertyName("files")] public required FilesInfoBody Files { get; init; }
+}
+
+public sealed class FilesInfoBody
+{
+    /// <summary>true 时,超过 threshold_bytes 的文件由客户端直接传给文件服务,主后端只登记元数据</summary>
+    [JsonPropertyName("enabled")] public bool Enabled { get; init; }
+    /// <summary>超过这个大小的文件才存到文件服务;未开启时为 0</summary>
+    [JsonPropertyName("url")] public string? Url { get; init; }
+}
+
+public sealed class FileGrantRequest
+{
+    /// <summary>create:创建文件域(空间所有者/管理员);put:上传某个条目;get:下载或播放某个条目;delete:删除某个条目的字节;domain:查询某个频道文件域的容量和用量</summary>
+    [JsonPropertyName("op")] public required string Op { get; init; }
+    /// <summary>put/get/delete 时的条目 id(base64url)</summary>
+    [JsonPropertyName("item")] public string? Item { get; init; }
+    /// <summary>domain 时的频道 id:查询这个频道文件域的容量和用量</summary>
+    [JsonPropertyName("channel")] public string? Channel { get; init; }
+    /// <summary>get 时从第几帧开始(0 才计一次下载)</summary>
+    [JsonPropertyName("from")] public long From { get; init; }
+}
+
+/// <summary>去文件服务用的凭证:地址、文件域 id(create 时为空)和一张短期票据</summary>
+public sealed class FileGrantBody
+{
+    [JsonPropertyName("url")] public required string Url { get; init; }
+    [JsonPropertyName("domain")] public required string Domain { get; init; }
+    [JsonPropertyName("ticket")] public required string Ticket { get; init; }
+    [JsonPropertyName("expires_at")] public long ExpiresAt { get; init; }
+}
+
+public sealed class DefaultsBody
+{
+    [JsonPropertyName("channel_mode")] public ChannelMode ChannelMode { get; init; } = CreationDefaults.ChannelMode;
+    [JsonPropertyName("channel")] public required ChannelSettings Channel { get; init; }
+    [JsonPropertyName("share")] public required ShareSettings Share { get; init; }
+}
+public sealed class SettingChoicesBody
+{
+    [JsonPropertyName("max_members")] public required int[] MaxMembers { get; init; }
+    [JsonPropertyName("ttl_seconds")] public required int[] TtlSeconds { get; init; }
+    [JsonPropertyName("file_max_downloads")] public int[] FileMaxDownloads { get; init; } = ServerSettingChoices.FileMaxDownloads;
+    [JsonPropertyName("max_visitors")] public required int[] MaxVisitors { get; init; }
+}
+
+/// <summary>告诉前端要不要出示验证码、widget 该连哪里(Cap 的 data-cap-api-endpoint)。</summary>
+public sealed class CaptchaBody
+{
+    [JsonPropertyName("provider")] public required string Provider { get; init; }
+    [JsonPropertyName("enabled")] public required bool Enabled { get; init; }
+    [JsonPropertyName("api_endpoint")] public string? ApiEndpoint { get; init; }
+}
+
+public sealed class TransportsBody
+{
+    [JsonPropertyName("websocket")] public bool WebSocket { get; init; } = true;
+    [JsonPropertyName("sse")] public bool Sse { get; init; } = true;
+    [JsonPropertyName("http3")] public required bool Http3 { get; init; }
+}
+
+public sealed class LimitsBody
+{
+    [JsonPropertyName("max_payload_bytes")] public required int MaxPayloadBytes { get; init; }
+    [JsonPropertyName("max_frames_per_item")] public required int MaxFramesPerItem { get; init; }
+    [JsonPropertyName("max_channel_bytes")] public required long MaxChannelBytes { get; init; }
+    [JsonPropertyName("max_workspace_bytes")] public required long MaxWorkspaceBytes { get; init; }
+    [JsonPropertyName("max_members")] public required int MaxMembers { get; init; }
+    [JsonPropertyName("max_ttl_seconds")] public required int MaxTtlSeconds { get; init; }
+    [JsonPropertyName("min_ttl_seconds")] public required int MinTtlSeconds { get; init; }
+    [JsonPropertyName("max_items")] public required int MaxItems { get; init; }
+    [JsonPropertyName("max_visitors")] public required int MaxVisitors { get; init; }
+}
+
+public sealed class AccountRegisterRequest
+{
+    [JsonPropertyName("public_key")] public required string PublicKey { get; init; }
+    [JsonPropertyName("signing_public_key")] public required string SigningPublicKey { get; init; }
+    [JsonPropertyName("username")] public required string Username { get; init; }
+    [JsonPropertyName("salt")] public required string Salt { get; init; }
+    [JsonPropertyName("verifier")] public required string Verifier { get; init; }
+    [JsonPropertyName("vault")] public required string Vault { get; init; }
+}
+public sealed class AccountSaltRequest { [JsonPropertyName("username")] public required string Username { get; init; } }
+public sealed class AccountSessionRequest
+{
+    [JsonPropertyName("device_id")] public string? DeviceId { get; init; }
+    [JsonPropertyName("device_name")] public string? DeviceName { get; init; }
+    [JsonPropertyName("username")] public required string Username { get; init; }
+    [JsonPropertyName("verifier")] public required string Verifier { get; init; }
+}
+public sealed class AccountVaultRequest
+{
+    [JsonPropertyName("revision")] public required long Revision { get; init; }
+    [JsonPropertyName("vault")] public required string Vault { get; init; }
+}
+public sealed class AccountSaltBody
+{
+    [JsonPropertyName("salt")] public required string Salt { get; init; }
+}
+public sealed class AccountSessionBody
+{
+    [JsonPropertyName("token")] public required string Token { get; init; }
+    [JsonPropertyName("username")] public required string Username { get; init; }
+}
+public sealed class AccountVaultBody
+{
+    [JsonPropertyName("revision")] public required long Revision { get; init; }
+    [JsonPropertyName("vault")] public required string Vault { get; init; }
+}
+
+public sealed class PublicKeyBody
+{
+    [JsonPropertyName("public_key")] public required string PublicKey { get; init; }
+    [JsonPropertyName("signing_public_key")] public string? SigningPublicKey { get; init; }
+}
+public sealed class InvitationRequest
+{
+    [JsonPropertyName("username")] public required string Username { get; init; }
+    [JsonPropertyName("payload")] public required string Payload { get; init; }
+    [JsonPropertyName("domain_envelopes")] public List<DomainEnvelope>? DomainEnvelopes { get; init; }
+}
+public sealed class InvitationBody
+{
+    [JsonPropertyName("channel_id")] public required string ChannelId { get; init; }
+    [JsonPropertyName("username")] public required string Username { get; init; }
+    [JsonPropertyName("payload")] public required string Payload { get; init; }
+    [JsonPropertyName("created_at")] public required long CreatedAt { get; init; }
+    /// <summary>调用者能不能撤销这条邀请(后端按权限判断)</summary>
+    [JsonPropertyName("can_revoke")] public bool CanRevoke { get; init; }
+}
+public sealed class JoinRequest { [JsonPropertyName("password")] public string? Password { get; init; } }
+public sealed class KeyPackageRequest { [JsonPropertyName("payload")] public required string Payload { get; init; } }
+public sealed class AccountDeviceNameRequest { [JsonPropertyName("name")] public required string Name { get; init; } }
+public sealed class AccountDeviceSigningRequest
+{
+    [JsonPropertyName("device_id")] public required string DeviceId { get; init; }
+    [JsonPropertyName("public_key")] public required string PublicKey { get; init; }
+    [JsonPropertyName("signature")] public required string Signature { get; init; }
+}
+public sealed class AccountDeviceBody
+{
+    [JsonPropertyName("id")] public required string Id { get; init; }
+    [JsonPropertyName("name")] public required string Name { get; init; }
+    [JsonPropertyName("created_at")] public required long CreatedAt { get; init; }
+    [JsonPropertyName("last_seen")] public required long LastSeen { get; init; }
+
+    [JsonPropertyName("current")] public required bool Current { get; init; }
+}
+public sealed class AccountChannelBody
+{
+    [JsonPropertyName("channel_id")] public required string ChannelId { get; init; }
+    [JsonPropertyName("role")] public required string Role { get; init; }
+    [JsonPropertyName("payload")] public required string Payload { get; init; }
+    [JsonPropertyName("created_at")] public required long CreatedAt { get; init; }
+}
+public sealed class MemberBody
+{
+    [JsonPropertyName("username")] public required string Username { get; init; }
+    [JsonPropertyName("role")] public required string Role { get; init; }
+    [JsonPropertyName("joined_at")] public required long JoinedAt { get; init; }
+
+    /// <summary>该账号此刻在本频道有至少一个活动订阅(WebSocket/SSE)。</summary>
+    [JsonPropertyName("online")] public required bool Online { get; init; }
+
+    /// <summary>该账号在本频道登记过的设备(终端)数;设备只是账号的属性,不是独立成员。</summary>
+    [JsonPropertyName("devices")] public required int Devices { get; init; }
+    [JsonPropertyName("online_devices")] public required int OnlineDevices { get; init; }
+
+    /// <summary>该账号任一设备最近一次活跃的 Unix 时间戳(登录时是秒,活跃续期后是毫秒,客户端按量级区分);没有登录过设备时为 0。</summary>
+    [JsonPropertyName("last_seen")] public required long LastSeen { get; init; }
+
+    /// <summary>调用者能不能移除这位成员(后端按权限判断)。</summary>
+    [JsonPropertyName("can_remove")] public bool CanRemove { get; init; }
+}
+
+public sealed class AccountProfileRequest
+{
+    [JsonPropertyName("displayName")] public required string DisplayName { get; init; }
+    [JsonPropertyName("avatar")] public string? Avatar { get; init; }
+    /// <summary>头像的有损小图(data URL)。列表、聊天默认只分发它,原图在预览时才下载</summary>
+    [JsonPropertyName("avatarThumb")] public string? AvatarThumb { get; init; }
+    /// <summary>只改名字、不动头像:保留服务端现有的头像(不带 avatar 的请求默认表示移除头像)</summary>
+    [JsonPropertyName("keepAvatar")] public bool KeepAvatar { get; init; }
+}
+public sealed class WorkspaceNameRequest { [JsonPropertyName("name")] public required string Name { get; init; } }
+public sealed class WorkspaceChannelRequest
+{
+    [JsonPropertyName("name")] public required string Name { get; init; }
+    [JsonPropertyName("groupId")] public string? GroupId { get; init; }
+    /// <summary>文件服务里为这个频道创建的文件域 id(不透明字符串,主后端只存不解释)</summary>
+    [JsonPropertyName("fileDomain")] public string? FileDomain { get; init; }
+}
+public sealed class WorkspaceFileDomainRequest { [JsonPropertyName("fileDomain")] public required string FileDomain { get; init; } }
+public sealed class WorkspaceRoleRequest
+{
+    [JsonPropertyName("name")] public required string Name { get; init; }
+    [JsonPropertyName("prefix")] public string? Prefix { get; init; }
+    [JsonPropertyName("suffix")] public string? Suffix { get; init; }
+    [JsonPropertyName("color")] public string? Color { get; init; }
+    [JsonPropertyName("permissions")] public required List<string> Permissions { get; init; }
+}
+public sealed class WorkspaceRoleMembersRequest { [JsonPropertyName("members")] public required List<string> Members { get; init; } }
+public sealed class WorkspaceRoleCreatedBody
+{
+    [JsonPropertyName("workspace")] public required WorkspaceBody Workspace { get; init; }
+    [JsonPropertyName("role")] public required WorkspaceRole Role { get; init; }
+}
+public sealed class WorkspaceGroupRequest { [JsonPropertyName("groupId")] public string? GroupId { get; init; } }
+public sealed class WorkspaceFolderRequest
+{
+    [JsonPropertyName("name")] public required string Name { get; init; }
+    [JsonPropertyName("threadId")] public required string ThreadId { get; init; }
+    [JsonPropertyName("parentId")] public string? ParentId { get; init; }
+}
+public sealed class WorkspaceMoveRequest
+{
+    [JsonPropertyName("itemIds")] public required string[] ItemIds { get; init; }
+    [JsonPropertyName("threadId")] public required string ThreadId { get; init; }
+    [JsonPropertyName("folderId")] public string? FolderId { get; init; }
+}
+public sealed class WorkspaceBody
+{
+    [JsonPropertyName("structure")] public required WorkspaceState Structure { get; init; }
+    [JsonPropertyName("people")] public required List<AccountProfile> People { get; init; }
+}
+public sealed class WorkspaceChannelCreatedBody
+{
+    [JsonPropertyName("workspace")] public required WorkspaceBody Workspace { get; init; }
+    [JsonPropertyName("channel")] public required WorkspaceChannel Channel { get; init; }
+}
+public sealed class WorkspaceGroupCreatedBody
+{
+    [JsonPropertyName("workspace")] public required WorkspaceBody Workspace { get; init; }
+    [JsonPropertyName("group")] public required WorkspaceGroup Group { get; init; }
+}
+
+[JsonSerializable(typeof(ErrorBody))]
+[JsonSerializable(typeof(CryptoState))]
+[JsonSerializable(typeof(DomainPublishRequest))]
+[JsonSerializable(typeof(ObjectEnvelope))]
+[JsonSerializable(typeof(ChannelHistoryRequest))]
+[JsonSerializable(typeof(PasskeyBeginRequest))]
+[JsonSerializable(typeof(PasskeyOptionsBody))]
+[JsonSerializable(typeof(PasskeyFinishRequest))]
+[JsonSerializable(typeof(PasskeyInfoBody))]
+[JsonSerializable(typeof(List<PasskeyInfoBody>))]
+[JsonSerializable(typeof(PasskeySessionBody))]
+[JsonSerializable(typeof(PasskeyEnvelopeRequest))]
+[JsonSerializable(typeof(AccountProfile))]
+[JsonSerializable(typeof(AccountProfileRequest))]
+[JsonSerializable(typeof(WorkspaceState))]
+[JsonSerializable(typeof(WorkspaceBody))]
+[JsonSerializable(typeof(WorkspaceChannelCreatedBody))]
+[JsonSerializable(typeof(WorkspaceGroupCreatedBody))]
+[JsonSerializable(typeof(WorkspaceNameRequest))]
+[JsonSerializable(typeof(WorkspaceChannelRequest))]
+[JsonSerializable(typeof(WorkspaceFileDomainRequest))]
+[JsonSerializable(typeof(WorkspaceGroupRequest))]
+[JsonSerializable(typeof(WorkspaceRoleRequest))]
+[JsonSerializable(typeof(WorkspaceRoleMembersRequest))]
+[JsonSerializable(typeof(WorkspaceRoleCreatedBody))]
+[JsonSerializable(typeof(WorkspaceFolderRequest))]
+[JsonSerializable(typeof(WorkspaceMoveRequest))]
+[JsonSerializable(typeof(GoneLogBody))]
+[JsonSerializable(typeof(ServerInfoBody))]
+[JsonSerializable(typeof(FileGrantRequest))]
+[JsonSerializable(typeof(FileGrantBody))]
+[JsonSerializable(typeof(ChannelInfo))]
+[JsonSerializable(typeof(List<ChannelInfo>))]
+[JsonSerializable(typeof(ShareInfo))]
+[JsonSerializable(typeof(CreateShareRequest))]
+[JsonSerializable(typeof(ShareSettingsPatch))]
+[JsonSerializable(typeof(FinishShareRequest))]
+[JsonSerializable(typeof(CreateChannelRequest))]
+[JsonSerializable(typeof(ChannelSettingsPatch))]
+[JsonSerializable(typeof(JoinResult))]
+[JsonSerializable(typeof(AppendResult))]
+[JsonSerializable(typeof(AccountRegisterRequest))]
+[JsonSerializable(typeof(AccountDeviceSigningRequest))]
+[JsonSerializable(typeof(AccountSaltRequest))]
+[JsonSerializable(typeof(AccountSessionRequest))]
+[JsonSerializable(typeof(AccountVaultRequest))]
+[JsonSerializable(typeof(AccountSaltBody))]
+[JsonSerializable(typeof(AccountSessionBody))]
+[JsonSerializable(typeof(AccountVaultBody))]
+[JsonSerializable(typeof(PublicKeyBody))]
+[JsonSerializable(typeof(InvitationRequest))]
+[JsonSerializable(typeof(InvitationCryptoPlan))]
+[JsonSerializable(typeof(List<InvitationBody>))]
+[JsonSerializable(typeof(JoinRequest))]
+[JsonSerializable(typeof(List<MemberBody>))]
+[JsonSerializable(typeof(KeyPackageRequest))]
+[JsonSerializable(typeof(List<AccountChannelBody>))]
+[JsonSerializable(typeof(AccountDeviceNameRequest))]
+[JsonSerializable(typeof(List<AccountDeviceBody>))]
+[JsonSourceGenerationOptions(DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull)]
+public sealed partial class ApiJson : JsonSerializerContext;

server/src/WebDrop.Api/Passkeys/PasskeyCeremonies.cs

@@ -0,0 +1,25 @@
+using System.Collections.Concurrent;
+using System.Security.Cryptography;
+using WebDrop.Core;
+
+namespace WebDrop.Api;
+
+public sealed record PasskeyCeremony(string Username, string Purpose, string State, string PrfSalt, string? SessionHash, DateTimeOffset Expires);
+public sealed class PasskeyCeremonies
+{
+    private readonly ConcurrentDictionary<string, PasskeyCeremony> _pending = new();
+    public string Put(PasskeyCeremony ceremony)
+    {
+        foreach (var entry in _pending) if (entry.Value.Expires <= DateTimeOffset.UtcNow) _pending.TryRemove(entry.Key, out _);
+        if (_pending.Count >= 1000) throw new WebDropException(ErrorCode.RateLimited);
+        var id = Codec.Encode(RandomNumberGenerator.GetBytes(32));
+        _pending[id] = ceremony; return id;
+    }
+    public PasskeyCeremony Take(string id, string username, string purpose, string? token)
+    {
+        if (string.IsNullOrEmpty(id) || id.Length > 100 || !_pending.TryRemove(id, out var ceremony) || ceremony.Expires <= DateTimeOffset.UtcNow
+            || ceremony.Username != username || ceremony.Purpose != purpose || ceremony.SessionHash != Hash(token)) throw new WebDropException(ErrorCode.BadRequest);
+        return ceremony;
+    }
+    public static string? Hash(string? token) => token is null ? null : Convert.ToHexString(SHA256.HashData(System.Text.Encoding.UTF8.GetBytes(token)));
+}

server/src/WebDrop.Api/Passkeys/PasskeyDtos.cs

@@ -0,0 +1,49 @@
+using System.Text.Json.Serialization;
+
+namespace WebDrop.Api;
+
+public sealed class PasskeyBeginRequest
+{
+    [JsonPropertyName("username")] public required string Username { get; init; }
+    [JsonPropertyName("verifier")] public string? Verifier { get; init; }
+}
+public sealed class PasskeyOptionsBody
+{
+    [JsonPropertyName("id")] public required string Id { get; init; }
+    [JsonPropertyName("options")] public required string Options { get; init; }
+    [JsonPropertyName("credentials")] public List<PasskeyInfoBody> Credentials { get; init; } = [];
+    [JsonPropertyName("prf_salt")] public string? PrfSalt { get; init; }
+}
+public sealed class PasskeyFinishRequest
+{
+    [JsonPropertyName("username")] public required string Username { get; init; }
+    [JsonPropertyName("id")] public required string Id { get; init; }
+    [JsonPropertyName("credential")] public required string Credential { get; init; }
+    [JsonPropertyName("name")] public string? Name { get; init; }
+    [JsonPropertyName("key_envelope")] public string? KeyEnvelope { get; init; }
+    [JsonPropertyName("device_id")] public string? DeviceId { get; init; }
+    [JsonPropertyName("device_name")] public string? DeviceName { get; init; }
+}
+public sealed class PasskeyInfoBody
+{
+    [JsonPropertyName("id")] public required string Id { get; init; }
+    [JsonPropertyName("name")] public required string Name { get; init; }
+    [JsonPropertyName("prf_salt")] public required string PrfSalt { get; init; }
+    [JsonPropertyName("can_recover")] public bool CanRecover { get; init; }
+    [JsonPropertyName("created_at")] public long CreatedAt { get; init; }
+}
+public sealed class PasskeySessionBody
+{
+    [JsonPropertyName("username")] public required string Username { get; init; }
+    [JsonPropertyName("token")] public required string Token { get; init; }
+    [JsonPropertyName("credential_id")] public required string CredentialId { get; init; }
+    [JsonPropertyName("prf_salt")] public required string PrfSalt { get; init; }
+    [JsonPropertyName("key_envelope")] public string? KeyEnvelope { get; init; }
+}
+public sealed class PasskeyEnvelopeRequest
+{
+    [JsonPropertyName("username")] public required string Username { get; init; }
+    [JsonPropertyName("id")] public required string Id { get; init; }
+    [JsonPropertyName("credential")] public required string Credential { get; init; }
+    [JsonPropertyName("key_envelope")] public required string KeyEnvelope { get; init; }
+}

server/src/WebDrop.Api/Passkeys/PasskeyUserStore.cs

@@ -0,0 +1,51 @@
+using System.Text.Json;
+using System.Text.Json.Serialization;
+using Microsoft.AspNetCore.Identity;
+using WebDrop.Core;
+using WebDrop.Storage;
+
+namespace WebDrop.Api;
+
+public sealed record PasskeyAccount(string Username);
+
+[JsonSerializable(typeof(UserPasskeyInfo))]
+public sealed partial class PasskeyStorageJson : JsonSerializerContext;
+
+/// <summary>Reuse the framework's WebAuthn verifier without replacing the existing account/session system.</summary>
+public sealed class PasskeyUserStore(SqliteAccountStore accounts) : IUserPasskeyStore<PasskeyAccount>
+{
+    private readonly Dictionary<string, string> _readVersions = [];
+    public void Dispose() { }
+    public Task<string> GetUserIdAsync(PasskeyAccount user, CancellationToken ct) => Task.FromResult(user.Username);
+    public Task<string?> GetUserNameAsync(PasskeyAccount user, CancellationToken ct) => Task.FromResult<string?>(user.Username);
+    public Task<string?> GetNormalizedUserNameAsync(PasskeyAccount user, CancellationToken ct) => Task.FromResult<string?>(user.Username.ToUpperInvariant());
+    public Task SetUserNameAsync(PasskeyAccount user, string? name, CancellationToken ct) => name == user.Username ? Task.CompletedTask : throw new NotSupportedException();
+    public Task SetNormalizedUserNameAsync(PasskeyAccount user, string? name, CancellationToken ct) => Task.CompletedTask;
+    public Task<IdentityResult> CreateAsync(PasskeyAccount user, CancellationToken ct) => throw new NotSupportedException();
+    public Task<IdentityResult> DeleteAsync(PasskeyAccount user, CancellationToken ct) => throw new NotSupportedException();
+    public Task<IdentityResult> UpdateAsync(PasskeyAccount user, CancellationToken ct) => Task.FromResult(IdentityResult.Success);
+    public Task<PasskeyAccount?> FindByIdAsync(string id, CancellationToken ct) => Task.FromResult(accounts.GetPublicKey(id) is null ? null : new PasskeyAccount(id.ToLowerInvariant()));
+    public Task<PasskeyAccount?> FindByNameAsync(string name, CancellationToken ct) => FindByIdAsync(name, ct);
+    public Task<PasskeyAccount?> FindByPasskeyIdAsync(byte[] id, CancellationToken ct) => Task.FromResult(accounts.Passkey(Codec.Encode(id)) is { } record ? new PasskeyAccount(record.Username) : null);
+    public Task<UserPasskeyInfo?> FindPasskeyAsync(PasskeyAccount user, byte[] id, CancellationToken ct)
+    {
+        var record = accounts.Passkey(Codec.Encode(id));
+        return Task.FromResult(record?.Username == user.Username ? Read(record) : null);
+    }
+    public Task<IList<UserPasskeyInfo>> GetPasskeysAsync(PasskeyAccount user, CancellationToken ct) => Task.FromResult<IList<UserPasskeyInfo>>(accounts.Passkeys(user.Username).Select(Read).ToList());
+    private UserPasskeyInfo Read(StoredPasskey record)
+    {
+        _readVersions[record.Id] = record.Data;
+        return JsonSerializer.Deserialize(record.Data, PasskeyStorageJson.Default.UserPasskeyInfo)!;
+    }
+    public Task AddOrUpdatePasskeyAsync(PasskeyAccount user, UserPasskeyInfo passkey, CancellationToken ct)
+    {
+        var id = Codec.Encode(passkey.CredentialId);
+        var latest = accounts.Passkey(id) ?? throw new WebDropException(ErrorCode.Unauthorized);
+        var previous = JsonSerializer.Deserialize(latest.Data, PasskeyStorageJson.Default.UserPasskeyInfo)!;
+        if ((previous.SignCount != 0 || passkey.SignCount != 0) && passkey.SignCount <= previous.SignCount) throw new WebDropException(ErrorCode.Unauthorized);
+        if (!_readVersions.TryGetValue(id, out var old) || !accounts.UpdatePasskeyData(id, user.Username, old, JsonSerializer.Serialize(passkey, PasskeyStorageJson.Default.UserPasskeyInfo))) throw new WebDropException(ErrorCode.Conflict);
+        return Task.CompletedTask;
+    }
+    public Task RemovePasskeyAsync(PasskeyAccount user, byte[] id, CancellationToken ct) { accounts.RemovePasskey(Codec.Encode(id), user.Username); return Task.CompletedTask; }
+}

server/src/WebDrop.Api/Realtime/ChannelHub.cs

@@ -0,0 +1,169 @@
+using WebDrop.Core;
+
+namespace WebDrop.Api;
+
+/// <summary>
+/// 进程内的订阅枢纽。只传递「有变化」的信号,订阅者被唤醒后自己从日志里按游标读取,
+/// 所以不存在回放与实时之间漏帧的竞态,也不需要为慢客户端缓冲数据。
+/// 因此只支持单实例部署(见 architecture.md)。
+/// </summary>
+public sealed class ChannelHub : IChannelEvents
+{
+    private readonly object _gate = new();
+    private readonly Dictionary<Id16, Signal> _signals = [];
+
+    // 账号级的「有频道前进了」信号:不管有没有人订阅这个频道都会记录,供空间列表上的未读提示用
+    private readonly Dictionary<Id16, long> _advanced = [];
+    private TaskCompletionSource _anyAdvanced = new(TaskCreationOptions.RunContinuationsAsynchronously);
+
+    // 在线状态:频道 -> 账号 -> 账号设备 -> 活动订阅数。只记账号。
+    private readonly Dictionary<Id16, Dictionary<string, Dictionary<string, int>>> _presence = [];
+
+    public Subscription Subscribe(Id16 id)
+    {
+        lock (_gate)
+        {
+            if (!_signals.TryGetValue(id, out var signal)) _signals[id] = signal = new Signal();
+            signal.Refs++;
+            return new Subscription(this, id, signal);
+        }
+    }
+
+    /// <summary>登记一个活动订阅,释放返回值即下线。只供成员接口读取,不向订阅流推送,以免改变流的线格式。</summary>
+    public IDisposable Connected(Id16 id, string account, string deviceKey)
+    {
+        string endpoint = deviceKey;
+        lock (_gate)
+        {
+            if (!_presence.TryGetValue(id, out var accounts)) _presence[id] = accounts = [];
+            if (!accounts.TryGetValue(account, out var endpoints)) accounts[account] = endpoints = [];
+            endpoints[endpoint] = endpoints.GetValueOrDefault(endpoint) + 1;
+        }
+        return new Connection(() => Disconnected(id, account, endpoint));
+    }
+
+    private void Disconnected(Id16 id, string account, string endpoint)
+    {
+        lock (_gate)
+        {
+            if (_presence.TryGetValue(id, out var accounts) && accounts.TryGetValue(account, out var endpoints) && endpoints.TryGetValue(endpoint, out int count))
+            {
+                if (count <= 1) endpoints.Remove(endpoint); else endpoints[endpoint] = count - 1;
+                if (endpoints.Count == 0) accounts.Remove(account);
+                if (accounts.Count == 0) _presence.Remove(id);
+            }
+        }
+    }
+
+    public (bool Online, int Devices) Presence(Id16 id, string account)
+    {
+        lock (_gate)
+        {
+            return _presence.TryGetValue(id, out var accounts) && accounts.TryGetValue(account, out var endpoints)
+                ? (endpoints.Count > 0, endpoints.Count) : (false, 0);
+        }
+    }
+
+    private sealed class Connection(Action release) : IDisposable
+    {
+        private Action? _release = release;
+        public void Dispose() => Interlocked.Exchange(ref _release, null)?.Invoke();
+    }
+
+    public void Advanced(Id16 channelId, long seq)
+    {
+        TaskCompletionSource old;
+        lock (_gate)
+        {
+            _advanced[channelId] = Math.Max(_advanced.GetValueOrDefault(channelId), seq);
+            old = _anyAdvanced;
+            _anyAdvanced = new(TaskCreationOptions.RunContinuationsAsynchronously);
+        }
+        old.TrySetResult();
+        Publish(channelId, s => s.Seq = Math.Max(s.Seq, seq));
+    }
+
+    /// <summary>先取这个任务、再读 <see cref="AdvancedSeq"/>,最后等待任务:不会漏掉中间的前进。</summary>
+    public Task AnyAdvanced { get { lock (_gate) return _anyAdvanced.Task; } }
+
+    /// <summary>本进程启动以来该频道见到的最大序号;没有见到过为 0。</summary>
+    public long AdvancedSeq(Id16 channelId) { lock (_gate) return _advanced.GetValueOrDefault(channelId); }
+    public void SettingsChanged(Id16 channelId) => Publish(channelId, s => s.SettingsVersion++);
+    public void MembersChanged(Id16 channelId) => Publish(channelId, s => s.MembersVersion++);
+    public void ChannelDeleted(Id16 channelId) => Publish(channelId, s => s.Deleted = true);
+
+    private void Publish(Id16 id, Action<Signal> mutate)
+    {
+        TaskCompletionSource? toComplete;
+        lock (_gate)
+        {
+            if (!_signals.TryGetValue(id, out var signal)) return; // 没有订阅者,无需通知
+            mutate(signal);
+            toComplete = signal.Replace();
+        }
+        toComplete.TrySetResult(); // 在锁外完成,避免续体在锁内运行
+    }
+
+    private void Release(Id16 id, Signal signal)
+    {
+        lock (_gate)
+        {
+            if (--signal.Refs == 0) _signals.Remove(id);
+        }
+    }
+
+    internal sealed class Signal
+    {
+        private TaskCompletionSource _tcs = New();
+        public int Refs;
+        public long Seq;
+        public int SettingsVersion;
+        public int MembersVersion;
+        public bool Deleted;
+
+        public Task Changed => _tcs.Task;
+
+        public TaskCompletionSource Replace()
+        {
+            var old = _tcs;
+            _tcs = New();
+            return old;
+        }
+
+        private static TaskCompletionSource New() => new(TaskCreationOptions.RunContinuationsAsynchronously);
+    }
+
+    /// <summary>
+    /// 用法:先取 <see cref="Changed"/>,再读状态,最后等待取到的那个任务。
+    /// 取任务之后发生的任何发布都会让它完成,不会丢通知。
+    /// </summary>
+    public sealed class Subscription : IDisposable
+    {
+        private readonly ChannelHub _hub;
+        private readonly Id16 _id;
+        private readonly Signal _signal;
+        private int _disposed;
+
+        internal Subscription(ChannelHub hub, Id16 id, Signal signal)
+        {
+            _hub = hub;
+            _id = id;
+            _signal = signal;
+        }
+
+        public Task Changed
+        {
+            get { lock (_hub._gate) return _signal.Changed; }
+        }
+
+        public (int Settings, int MaxMembers, bool Deleted) State
+        {
+            get { lock (_hub._gate) return (_signal.SettingsVersion, _signal.MembersVersion, _signal.Deleted); }
+        }
+
+        public void Dispose()
+        {
+            if (Interlocked.Exchange(ref _disposed, 1) == 0) _hub.Release(_id, _signal);
+        }
+    }
+}

server/src/WebDrop.Api/Realtime/LogStreamer.cs

@@ -29,8 +29,9 @@ public static class LogStreamer
     {
         using var sub = hub.Subscribe(id);
         ILogSink? sink = null;
+        IDisposable? presence = null;
         long cursor = from;
-        var (settingsV, seatsV, _) = sub.State;
+        var (settingsV, membersV, _) = sub.State;
 
         try
         {
@@ -40,6 +41,8 @@ public static class LogStreamer
                 var changed = sub.Changed; // 先取任务再读状态:读取期间的发布不会丢
                 var page = await svc.ReadLogAsync(id, creds, cursor, PageSize, ct).ConfigureAwait(false);
                 sink ??= await open().ConfigureAwait(false);
+                // 鉴权与首次读取都成功之后才算在线
+                presence ??= hub.Connected(id, creds.AccountName!, creds.AccountDeviceId ?? "");
 
                 foreach (var record in page.Records)
                 {
@@ -47,16 +50,16 @@ public static class LogStreamer
                     cursor = record.Seq + 1;
                 }
 
-                var (settingsNow, seatsNow, deleted) = sub.State;
+                var (settingsNow, membersNow, deleted) = sub.State;
                 if (settingsNow != settingsV)
                 {
                     settingsV = settingsNow;
                     await sink.SendControlAsync("""{"t":"settings"}""", ct).ConfigureAwait(false);
                 }
-                if (seatsNow != seatsV)
+                if (membersNow != membersV)
                 {
-                    seatsV = seatsNow;
-                    await sink.SendControlAsync("""{"t":"seats"}""", ct).ConfigureAwait(false);
+                    membersV = membersNow;
+                    await sink.SendControlAsync("""{"t":"members"}""", ct).ConfigureAwait(false);
                 }
                 if (deleted) throw new WebDropException(ErrorCode.NotFound);
 
@@ -80,6 +83,10 @@ public static class LogStreamer
         {
             await sink.FailAsync(e.Code, CancellationToken.None).ConfigureAwait(false);
         }
+        finally
+        {
+            presence?.Dispose();
+        }
     }
 }
 

server/src/WebDrop.Api/WebDrop.Api.csproj

@@ -13,6 +13,7 @@
     <ProjectReference Include="..\WebDrop.Core\WebDrop.Core.csproj" />
     <ProjectReference Include="..\WebDrop.Frontend\WebDrop.Frontend.csproj" />
     <ProjectReference Include="..\WebDrop.Storage\WebDrop.Storage.csproj" />
+    <ProjectReference Include="..\WebDrop.Sync\WebDrop.Sync.csproj" />
   </ItemGroup>
 
 </Project>

server/src/WebDrop.Core/Abstractions/Abstractions.cs

@@ -42,7 +42,7 @@ public interface IChannelEvents
 {
     void Advanced(Id16 channelId, long seq);
     void SettingsChanged(Id16 channelId);
-    void SeatsChanged(Id16 channelId);
+    void MembersChanged(Id16 channelId);
     void ChannelDeleted(Id16 channelId);
 }
 
@@ -50,7 +50,7 @@ public sealed class NullChannelEvents : IChannelEvents
 {
     public void Advanced(Id16 channelId, long seq) { }
     public void SettingsChanged(Id16 channelId) { }
-    public void SeatsChanged(Id16 channelId) { }
+    public void MembersChanged(Id16 channelId) { }
     public void ChannelDeleted(Id16 channelId) { }
 }
 
@@ -91,6 +91,11 @@ public interface IResourceTx
     // 频道
     Channel? GetChannel(Id16 id);
     void InsertChannel(Channel channel);
+    WorkspaceState? GetWorkspace(Id16 id);
+    CryptoState GetWorkspaceCrypto(Id16 id);
+    void PutWorkspaceCrypto(Id16 id, CryptoState state);
+    IReadOnlyList<Id16> ListAccountSpaces(string username, long now);
+    void PutWorkspace(Id16 id, WorkspaceState state);
     void UpdateChannel(Id16 id, ChannelSettings settings, long expiresAt);
     void SetJoinPassword(Id16 id, byte[]? hash, byte[]? salt);
     bool HasInvitation(Id16 id, string username);
@@ -101,31 +106,28 @@ public interface IResourceTx
     void PutKeyPackage(Id16 id, string username, string payload, long createdAt);
     void DeleteKeyPackage(Id16 id, string username);
     IReadOnlyList<ChannelKeyPackage> ListUserKeyPackages(string username, long now);
-    IReadOnlyList<Id16> DeleteDeviceSeats(string username, string deviceId);
-    void BindSeatDevice(Id16 id, byte[] endpointHash, string deviceId);
-    void DeleteAccountSeats(Id16 id, string username);
     ChannelMember? GetChannelMember(Id16 id, string username);
     IReadOnlyList<ChannelMember> ListChannelMembers(Id16 id);
     void PutChannelMember(Id16 id, ChannelMember member);
     void DeleteChannelMember(Id16 id, string username);
-    bool IsJoinDenied(Id16 id, string? username, byte[] endpointHash);
+    bool IsJoinDenied(Id16 id, string username);
     void DenyAccount(Id16 id, string username);
     void AllowAccount(Id16 id, string username);
-    void DenyEndpoint(Id16 id, byte[] endpointHash);
     void TouchChannel(Id16 id, long expiresAt);
     void AddChannelBytes(Id16 id, long delta);
     void SetCompactedThrough(Id16 id, long seq);
     long NextSeq(Id16 id);
     void DeleteChannelRows(Id16 id);
+    /// <summary>空间头像(data URL)单独存放,不放进每次请求都要读的设置 JSON</summary>
+    /// <summary>thumb 为 true 取缩略图(没有就用原图),否则取原图</summary>
+    AvatarBlob? GetChannelAvatar(Id16 id, bool thumb);
+    /// <summary>头像的版本标记(头像文件名,内容变了才会变);没有头像为 null</summary>
+    string? GetChannelAvatarVersion(Id16 id);
+    void SetChannelAvatar(Id16 id, string? avatar, string? thumb);
     IReadOnlyList<Id16> ListExpiredChannels(long now, int limit);
 
-    // 席位
-    Seat? GetSeat(Id16 channelId, ReadOnlySpan<byte> endpointHash);
-    int CountSeats(Id16 channelId);
-    void InsertSeat(Id16 channelId, Seat seat);
-    bool DeleteSeat(Id16 channelId, ReadOnlySpan<byte> endpointHash);
-    void SetSeatLabel(Id16 channelId, ReadOnlySpan<byte> endpointHash, byte[] label);
-    IReadOnlyList<Seat> ListSeats(Id16 channelId);
+    // 成员
+    int CountMembers(Id16 channelId);
 
     // 条目
     Item? GetItem(Id16 channelId, Id16 itemId);

server/src/WebDrop.Core/Accounts/AccountProfile.cs

@@ -0,0 +1,18 @@
+using System.Text.Json.Serialization;
+
+namespace WebDrop.Core;
+
+public sealed class AccountProfile
+{
+    [JsonPropertyName("username")] public required string Username { get; init; }
+    [JsonPropertyName("displayName")] public required string DisplayName { get; init; }
+    /// <summary>头像文件名(服务端存的是磁盘文件)。资料列表、空间成员等接口不再内联头像(动图可能有几 MB),只告诉有没有,头像另用 /accounts/users/{用户名}/avatar 取</summary>
+    [JsonPropertyName("avatar")] public string? Avatar { get; init; }
+    [JsonPropertyName("hasAvatar")] public bool HasAvatar { get; init; }
+    [JsonPropertyName("modifiedAt")] public required long ModifiedAt { get; init; }
+
+    /// <summary>有损的小图(列表、聊天里默认分发);没有单独上传时用原图。不随 JSON 输出</summary>
+    [JsonIgnore] public string? AvatarThumb { get; init; }
+
+    public AccountProfile WithoutAvatar() => new() { Username = Username, DisplayName = DisplayName, HasAvatar = HasAvatar, ModifiedAt = ModifiedAt };
+}

server/src/WebDrop.Core/Accounts/AvatarData.cs

@@ -0,0 +1,35 @@
+namespace WebDrop.Core;
+
+/// <summary>头像(账号头像、空间头像)的 data URL 校验。浏览器里已经裁剪好并重新编码,服务端只做格式、大小和文件头检查</summary>
+public static class AvatarData
+{
+    /// <summary>静态头像(256×256 WebP/PNG/JPEG)的长度上限(字符数)</summary>
+    public const int MaxStaticChars = 350_000;
+    /// <summary>账号动图头像保留全部帧,约 4.5 MB</summary>
+    public const int MaxAccountGifChars = 6_000_000;
+    /// <summary>空间头像会跟着空间信息发给所有成员和空间列表,动图上限比账号头像小,约 1.5 MB</summary>
+    public const int MaxSpaceGifChars = 2_000_000;
+
+    /// <summary>缩略图(列表、聊天里默认分发的有损小图)的上限:静态约 75 KB,动图约 370 KB</summary>
+    public const int MaxThumbStaticChars = 100_000;
+    public const int MaxThumbGifChars = 800_000;
+
+    private static readonly string[] Prefixes = ["data:image/png;base64,", "data:image/jpeg;base64,", "data:image/webp;base64,", "data:image/gif;base64,"];
+
+    public static void ValidateThumb(string thumb) => Validate(thumb, MaxThumbGifChars, MaxThumbStaticChars);
+
+    /// <summary>不合法时抛 BadRequest</summary>
+    public static void Validate(string avatar, int maxGifChars, int maxStaticChars = MaxStaticChars)
+    {
+        var prefix = Prefixes.FirstOrDefault(p => avatar.StartsWith(p, StringComparison.Ordinal));
+        var gif = prefix?.Contains("gif", StringComparison.Ordinal) == true;
+        if (prefix is null || avatar.Length > (gif ? maxGifChars : maxStaticChars) || avatar.Length <= prefix.Length) throw new WebDropException(ErrorCode.BadRequest);
+        byte[] bytes;
+        try { bytes = Convert.FromBase64String(avatar[prefix.Length..]); }
+        catch (FormatException) { throw new WebDropException(ErrorCode.BadRequest); }
+        if (gif && !(bytes.Length > 6 && bytes[0] == (byte)'G' && bytes[1] == (byte)'I' && bytes[2] == (byte)'F')) throw new WebDropException(ErrorCode.BadRequest);
+    }
+}
+
+/// <summary>落在磁盘上的头像文件:下载时直接按路径发送,不读进内存。Hash 是内容的 SHA-256,也用作 ETag</summary>
+public sealed record AvatarBlob(string Path, string Mime, string Hash);

server/src/WebDrop.Core/ChannelAdmission.cs

@@ -1,99 +0,0 @@
-using System.Security.Cryptography;
-
-namespace WebDrop.Core;
-
-public sealed partial class ChannelService
-{
-    private static (byte[]? Hash, byte[]? Salt) HashJoinPassword(string? password)
-    {
-        if (string.IsNullOrEmpty(password)) return (null, null);
-        if (password.Length is < 8 or > 256) throw new WebDropException(ErrorCode.BadRequest);
-        var salt = RandomNumberGenerator.GetBytes(16);
-        return (Rfc2898DeriveBytes.Pbkdf2(password, salt, 210_000, HashAlgorithmName.SHA256, 32), salt);
-    }
-
-    private static void CheckAdmission(IResourceTx tx, Channel channel, Credentials creds, string? password)
-    {
-        if (creds.AccountName is not null && creds.AccountName == channel.CreatorAccount) return;
-        if (tx.IsJoinDenied(channel.Id, creds.AccountName, creds.EndpointHash)) throw new WebDropException(ErrorCode.Forbidden);
-        bool invited = creds.AccountName is not null && tx.HasInvitation(channel.Id, creds.AccountName);
-        if (invited) return;
-        if (creds.AccountName is not null && tx.GetChannelMember(channel.Id, creds.AccountName) is not null) return;
-        if (channel.Settings.JoinPolicy == "invite") throw new WebDropException(ErrorCode.InvitationRequired);
-        if (!channel.Settings.AllowGuests && creds.AccountName is null) throw new WebDropException(ErrorCode.AccountRequired);
-        if (channel.JoinPasswordHash is null) return;
-        if (string.IsNullOrEmpty(password)) throw new WebDropException(ErrorCode.ChannelPasswordRequired);
-        if (password.Length > 256) throw new WebDropException(ErrorCode.ChannelPasswordInvalid);
-        var actual = Rfc2898DeriveBytes.Pbkdf2(password, channel.JoinPasswordSalt!, 210_000, HashAlgorithmName.SHA256, 32);
-        if (!CryptographicOperations.FixedTimeEquals(actual, channel.JoinPasswordHash)) throw new WebDropException(ErrorCode.ChannelPasswordInvalid);
-    }
-
-    public void InviteUser(Id16 id, Credentials creds, string username, string payload)
-    {
-        if (payload is null || payload.Length is < 1 or > 16_384) throw new WebDropException(ErrorCode.BadRequest);
-        store.Write(tx =>
-        {
-            var (_, principal) = Authenticate(tx, id, creds, SeatRule.None);
-            RequireOwner(principal);
-            tx.PutInvitation(new ChannelInvitation(id, username, payload, clock.NowMs));
-            if (tx.GetChannelMember(id, username)?.Role == "owner") throw new WebDropException(ErrorCode.Forbidden);
-            tx.PutKeyPackage(id, username, payload, clock.NowMs);
-            tx.AllowAccount(id, username);
-            return 0;
-        });
-    }
-
-    public IReadOnlyList<ChannelInvitation> Invitations(Id16 id, Credentials creds) => store.Read(tx =>
-    {
-        var (_, principal) = Authenticate(tx, id, creds, SeatRule.None);
-        RequireOwner(principal);
-        return tx.ListInvitations(id);
-    });
-
-    public IReadOnlyList<ChannelInvitation> UserInvitations(string username) => store.Read(tx => tx.ListUserInvitations(username));
-
-    public void RevokeInvitation(Id16 id, Credentials creds, string username)
-    {
-        store.Write(tx =>
-        {
-            var (_, principal) = Authenticate(tx, id, creds, SeatRule.None);
-            RequireOwner(principal);
-            if (tx.GetChannelMember(id, username)?.Role == "owner") throw new WebDropException(ErrorCode.Forbidden);
-            tx.DeleteInvitation(id, username);
-            tx.DeleteKeyPackage(id, username);
-            tx.DeleteAccountSeats(id, username);
-            tx.DeleteChannelMember(id, username);
-            tx.DenyAccount(id, username);
-            return 0;
-        });
-        events.SeatsChanged(id);
-    }
-
-    public IReadOnlyList<ChannelMember> Members(Id16 id, Credentials creds) => store.Read(tx =>
-    {
-        var (_, principal) = Authenticate(tx, id, creds, SeatRule.None);
-        if (principal.Role != Role.Owner) _ = Authenticate(tx, id, creds, SeatRule.Required);
-        return tx.ListChannelMembers(id);
-    });
-
-    public IReadOnlyList<ChannelKeyPackage> AccountChannels(string username) =>
-        store.Read(tx => tx.ListUserKeyPackages(username, clock.NowMs));
-
-    public void ReleaseAccountDevice(string username, string deviceId)
-    {
-        var channels = store.Write(tx => tx.DeleteDeviceSeats(username, deviceId));
-        foreach (var id in channels) events.SeatsChanged(id);
-    }
-
-    public void SaveOwnerKeyPackage(Id16 id, Credentials creds, string payload)
-    {
-        if (payload is null || payload.Length is < 1 or > 16_384) throw new WebDropException(ErrorCode.BadRequest);
-        store.Write(tx =>
-        {
-            var (_, principal) = Authenticate(tx, id, creds, SeatRule.None);
-            RequireOwner(principal);
-            tx.PutKeyPackage(id, principal.AccountName!, payload, clock.NowMs);
-            return 0;
-        });
-    }
-}

server/src/WebDrop.Core/ChannelPolicy.cs

@@ -1,28 +0,0 @@
-namespace WebDrop.Core;
-
-/// <summary>谁能做什么。规则只写在这里,服务和测试都调用它。</summary>
-public static class ChannelPolicy
-{
-    public static bool IsOwner(Principal p) => p.Role == Role.Owner;
-
-    public static bool CanRead(Principal p) => p.Role >= Role.Read;
-
-    /// <summary>成员写入需要频道允许上传,且服务端持有写令牌哈希。</summary>
-    public static bool CanWrite(Channel channel, Principal p) =>
-        p.Role == Role.Owner
-        || (p.Role == Role.Write && channel.Settings.MembersCanUpload && channel.WriteHash is not null);
-
-    public static bool CanDeleteItem(Channel channel, Item item, Principal p)
-    {
-        if (p.Role == Role.Owner) return true;
-        if (p.Role < Role.Read) return false;
-        return channel.Settings.DeletePolicy switch
-        {
-            DeletePolicy.Anyone => true,
-            DeletePolicy.Own => item.AuthorAccount is not null
-                ? item.AuthorAccount == p.AccountName
-                : item.AuthorHash.AsSpan().SequenceEqual(p.EndpointHash),
-            _ => false,
-        };
-    }
-}

server/src/WebDrop.Core/ChannelService.cs

@@ -1,634 +0,0 @@
-using System.Security.Cryptography;
-
-namespace WebDrop.Core;
-
-/// <summary>
-/// 频道的全部业务逻辑。依赖抽象(存储、blob、时钟、事件),不含 HTTP、SQL、文件细节。
-/// 约定:所有失败以 <see cref="WebDropException"/> 表达;提交成功后才发事件;blob 先写后提交。
-/// </summary>
-public sealed partial class ChannelService(
-    IResourceStore store,
-    IBlobStore blobs,
-    IClock clock,
-    ServerLimits limits,
-    IChannelEvents events)
-{
-    private enum SeatRule { None, Required }
-
-    // ───────────────────────── 频道 ─────────────────────────
-
-    public ChannelInfo CreateChannel(CreateChannelRequest req, byte[] endpointHash, string creatorAccount, string? accountDeviceId = null)
-    {
-        if (string.IsNullOrWhiteSpace(creatorAccount)) throw new WebDropException(ErrorCode.AccountRequired);
-        if (req.KeyPackage is not null && req.KeyPackage.Length is < 1 or > 16_384) throw new WebDropException(ErrorCode.BadRequest);
-        if (!Id16.TryParse(req.Id, out var id)) throw new WebDropException(ErrorCode.BadRequest);
-        if (req.Mode is not { } mode) throw new WebDropException(ErrorCode.BadRequest);
-
-        var settings = req.Settings ?? new ChannelSettings();
-        settings.Validate(limits);
-
-        if (!Codec.TryDecodeExact(req.OwnerHash, TokenHash.Size, out var ownerHash))
-            throw new WebDropException(ErrorCode.BadRequest);
-
-        byte[]? readHash = null;
-        if (mode == ChannelMode.Enc)
-        {
-            if (!Codec.TryDecodeExact(req.ReadHash, TokenHash.Size, out readHash))
-                throw new WebDropException(ErrorCode.BadRequest);
-        }
-        else if (req.ReadHash is not null)
-        {
-            throw new WebDropException(ErrorCode.BadRequest); // raw 频道的读权限是 id 本身
-        }
-
-        byte[]? writeHash = null;
-        if (req.WriteHash is not null && !Codec.TryDecodeExact(req.WriteHash, TokenHash.Size, out writeHash))
-            throw new WebDropException(ErrorCode.BadRequest);
-
-        long now = clock.NowMs;
-        var (passwordHash, passwordSalt) = HashJoinPassword(req.JoinPassword);
-        var channel = new Channel(id, mode, settings, readHash, writeHash, ownerHash,
-            now, now + settings.TtlSeconds * 1000L, 0, 0, 0, creatorAccount, passwordHash, passwordSalt);
-
-        store.Write(tx =>
-        {
-            if (tx.HasResourceId(id)) throw new WebDropException(ErrorCode.Conflict);
-            tx.InsertChannel(channel);
-            tx.PutChannelMember(id, new ChannelMember(creatorAccount, "owner", now));
-            if (req.KeyPackage is not null) tx.PutKeyPackage(id, creatorAccount, req.KeyPackage, now);
-            tx.InsertSeat(id, new Seat(endpointHash, now, null, creatorAccount, accountDeviceId));
-            return 0;
-        });
-        return ToInfo(channel, 1);
-    }
-
-    public ChannelInfo GetChannel(Id16 id, Credentials creds) => store.Read(tx =>
-    {
-        var (channel, _) = Authenticate(tx, id, creds, SeatRule.None);
-        return ToInfo(channel, tx.CountSeats(id));
-    });
-
-    public ChannelInfo UpdateSettings(Id16 id, Credentials creds, ChannelSettingsPatch patch)
-    {
-        var info = store.Write(tx =>
-        {
-            var (channel, principal) = Authenticate(tx, id, creds, SeatRule.None);
-            RequireOwner(principal);
-
-            var updated = patch.ApplyTo(channel.Settings);
-            updated.Validate(limits);
-
-            long expiresAt = updated.TtlSeconds != channel.Settings.TtlSeconds
-                ? clock.NowMs + updated.TtlSeconds * 1000L
-                : channel.ExpiresAt;
-            tx.UpdateChannel(id, updated, expiresAt);
-            if (patch.JoinPassword is not null)
-            {
-                var (hash, salt) = HashJoinPassword(patch.JoinPassword);
-                tx.SetJoinPassword(id, hash, salt);
-                channel = channel with { JoinPasswordHash = hash, JoinPasswordSalt = salt };
-            }
-            return ToInfo(channel with { Settings = updated, ExpiresAt = expiresAt }, tx.CountSeats(id));
-        });
-        events.SettingsChanged(id);
-        return info;
-    }
-
-    public void DeleteChannel(Id16 id, Credentials creds)
-    {
-        store.Write(tx =>
-        {
-            var (_, principal) = Authenticate(tx, id, creds, SeatRule.None);
-            RequireOwner(principal);
-            tx.DeleteChannelRows(id);
-            return 0;
-        });
-        blobs.DeletePrefix(id.ToHex());
-        events.ChannelDeleted(id);
-    }
-
-    // ───────────────────────── 席位 ─────────────────────────
-
-    public SeatJoined Join(Id16 id, Credentials creds, string? password = null)
-    {
-        var (joined, isNew) = store.Write(tx =>
-        {
-            var (channel, principal) = Authenticate(tx, id, creds, SeatRule.None);
-            var existing = tx.GetSeat(id, principal.EndpointHash);
-            if (existing?.AccountName is not null && existing.AccountName != creds.AccountName) throw new WebDropException(ErrorCode.AccountRequired);
-            if (existing?.AccountDeviceId is not null && existing.AccountDeviceId != creds.AccountDeviceId) throw new WebDropException(ErrorCode.AccountRequired);
-            int used = tx.CountSeats(id);
-            if (existing is not null)
-            {
-                if (existing.AccountName is not null && existing.AccountDeviceId is null && creds.AccountDeviceId is not null)
-                    tx.BindSeatDevice(id, principal.EndpointHash, creds.AccountDeviceId);
-                return (new SeatJoined { EndpointHash = Codec.Encode(existing.EndpointHash), JoinedAt = existing.JoinedAt, SeatsUsed = used, SeatsMax = channel.Settings.Seats }, false);
-            }
-
-            CheckAdmission(tx, channel, creds, password);
-
-            if (used >= channel.Settings.Seats) throw new WebDropException(ErrorCode.SeatsFull);
-            long now = clock.NowMs;
-            tx.InsertSeat(id, new Seat(principal.EndpointHash, now, null, creds.AccountName, creds.AccountDeviceId));
-            if (creds.AccountName is not null) tx.PutChannelMember(id, new ChannelMember(creds.AccountName, "member", now));
-            return (new SeatJoined { EndpointHash = Codec.Encode(principal.EndpointHash), JoinedAt = now, SeatsUsed = used + 1, SeatsMax = channel.Settings.Seats }, true);
-        });
-        if (isNew) events.SeatsChanged(id);
-        return joined;
-    }
-
-    public IReadOnlyList<SeatInfo> ListSeats(Id16 id, Credentials creds) => store.Read(tx =>
-    {
-        var (_, principal) = Authenticate(tx, id, creds, SeatRule.None);
-        RequireOwner(principal);
-        return (IReadOnlyList<SeatInfo>)tx.ListSeats(id).Select(s => new SeatInfo
-        {
-            EndpointHash = Codec.Encode(s.EndpointHash),
-            JoinedAt = s.JoinedAt,
-            Label = s.Label is null ? null : Codec.Encode(s.Label),
-            AccountName = s.AccountName,
-        }).ToList();
-    });
-
-    public void SetSeatLabel(Id16 id, Credentials creds, byte[] label)
-    {
-        ValidateSeatLabel(label);
-        store.Write(tx =>
-        {
-            var (_, principal) = Authenticate(tx, id, creds, SeatRule.Required);
-            tx.SetSeatLabel(id, principal.EndpointHash, label);
-            return 0;
-        });
-        events.SeatsChanged(id);
-    }
-
-    public void SetSeatLabelForEndpoint(Id16 id, Credentials creds, byte[] endpointHash, byte[] label)
-    {
-        ValidateSeatLabel(label);
-        store.Write(tx =>
-        {
-            var (_, principal) = Authenticate(tx, id, creds, SeatRule.None);
-            RequireOwner(principal);
-            if (tx.GetSeat(id, endpointHash) is null) throw new WebDropException(ErrorCode.NotFound);
-            tx.SetSeatLabel(id, endpointHash, label);
-            return 0;
-        });
-        events.SeatsChanged(id);
-    }
-
-    private void ValidateSeatLabel(byte[] label)
-    {
-        if (label.Length == 0) throw new WebDropException(ErrorCode.BadRequest);
-        if (label.Length > limits.MaxSeatLabelBytes) throw new WebDropException(ErrorCode.TooLarge);
-    }
-
-    public void ReleaseSeat(Id16 id, Credentials creds, byte[] endpointHash)
-    {
-        store.Write(tx =>
-        {
-            var (_, principal) = Authenticate(tx, id, creds, SeatRule.None);
-            RequireOwner(principal);
-            if (!tx.DeleteSeat(id, endpointHash)) throw new WebDropException(ErrorCode.NotFound);
-            tx.DenyEndpoint(id, endpointHash);
-            return 0;
-        });
-        events.SeatsChanged(id);
-    }
-
-    // ───────────────────────── 追加帧 ─────────────────────────
-
-    public async Task<AppendResult> AppendFrameAsync(
-        Id16 channelId, Credentials creds, ReadOnlyMemory<byte> body,
-        long? maxDownloads, CancellationToken ct = default)
-    {
-        if (!Envelope.TryParse(body.Span, out var env)) throw new WebDropException(ErrorCode.BadRequest);
-        if (env.PayloadLength > limits.MaxPayloadBytes) throw new WebDropException(ErrorCode.TooLarge);
-        ValidateShape(env);
-
-        byte[] digest = SHA256.HashData(body.Span);
-
-        // 1. 预检:鉴权并处理幂等重发,避免为重复帧白写 blob
-        var existing = store.Read(tx =>
-        {
-            var (channel, principal) = Authenticate(tx, channelId, creds, SeatRule.Required);
-            CheckWritable(channel, principal, env);
-            return tx.GetFrame(channelId, env.ItemId, env.FrameIndex);
-        });
-        if (existing is not null) return Resolve(existing, digest);
-
-        // 2. 大帧先写 blob。键含摘要,内容不同的并发写不会互相覆盖
-        string? blobKey = null;
-        if (body.Length >= limits.InlineThresholdBytes)
-        {
-            blobKey = $"{channelId.ToHex()}/{env.ItemId.ToHex()}/{env.FrameIndex}.{Convert.ToHexStringLower(digest.AsSpan(0, 16))}";
-            await blobs.PutAsync(blobKey, body, ct).ConfigureAwait(false);
-        }
-
-        // 3. 单事务提交
-        AppendOutcome outcome;
-        try
-        {
-            outcome = store.Write(tx => AppendInTx(tx, channelId, creds, env, body, digest, blobKey, maxDownloads));
-        }
-        catch
-        {
-            DeleteBlobIfUnreferenced(blobKey);
-            throw;
-        }
-
-        if (!outcome.Result.Created) DeleteBlobIfUnreferenced(blobKey);
-        foreach (string prefix in outcome.BlobPrefixesToDelete) blobs.DeletePrefix(prefix);
-        events.Advanced(channelId, outcome.LastSeq);
-        return outcome.Result;
-    }
-
-    private sealed class AppendOutcome(AppendResult result, long lastSeq, List<string> prefixes)
-    {
-        public AppendResult Result { get; } = result;
-        public long LastSeq { get; } = lastSeq;
-        public List<string> BlobPrefixesToDelete { get; } = prefixes;
-    }
-
-    private AppendOutcome AppendInTx(
-        IResourceTx tx, Id16 channelId, Credentials creds, Envelope env, ReadOnlyMemory<byte> body,
-        byte[] digest, string? blobKey, long? maxDownloads)
-    {
-        var (channel, principal) = Authenticate(tx, channelId, creds, SeatRule.Required);
-        CheckWritable(channel, principal, env);
-
-        // 并发下预检之后可能已有同一帧
-        if (tx.GetFrame(channelId, env.ItemId, env.FrameIndex) is { } dup)
-            return new AppendOutcome(Resolve(dup, digest), dup.Seq, []);
-
-        long now = clock.NowMs;
-        long ttlMs = channel.Settings.TtlSeconds * 1000L;
-        var item = tx.GetItem(channelId, env.ItemId);
-
-        if (env.FrameIndex == 0)
-        {
-            if (env.IsControl && tx.CountControlItems(channelId) >= 4096) throw new WebDropException(ErrorCode.TooLarge);
-            if (item is not null) throw new WebDropException(ErrorCode.BadRequest);
-            long max = env.IsGated ? Math.Clamp(maxDownloads ?? channel.Settings.FileMaxDownloads, 0, 1_000_000) : 0;
-            item = new Item(channelId, env.ItemId, principal.EndpointHash, env.ItemFlags, max, 0, 0, -1, null, 0,
-                now, env.IsControl ? long.MaxValue : now + ttlMs, null, principal.AccountName);
-            tx.InsertItem(item);
-        }
-        else
-        {
-            if (item is null) throw new WebDropException(ErrorCode.BadRequest);
-            if (item.Flags != env.ItemFlags) throw new WebDropException(ErrorCode.BadRequest);
-            if (item.CloseDeadline is not null) throw new WebDropException(ErrorCode.Gone);
-            if (item.FinalIndex is { } fi && env.FrameIndex > fi) throw new WebDropException(ErrorCode.BadRequest);
-        }
-
-        if (env.FrameIndex >= limits.MaxFramesPerItem) throw new WebDropException(ErrorCode.TooLarge);
-        if (env.IsFinal)
-        {
-            if (item.MaxIndex > env.FrameIndex) throw new WebDropException(ErrorCode.BadRequest);
-            if (item.FinalIndex is { } f && f != env.FrameIndex) throw new WebDropException(ErrorCode.BadRequest);
-        }
-        if (channel.Bytes + body.Length > limits.MaxChannelBytes) throw new WebDropException(ErrorCode.TooLarge);
-
-        long seq = tx.NextSeq(channelId);
-        tx.InsertFrame(new StoredFrame(channelId, env.ItemId, env.FrameIndex, seq, body.Length, digest,
-            blobKey is null ? body.ToArray() : null, blobKey));
-
-        if (!env.IsGated)
-            tx.InsertLog(channelId, new LogEntry(seq, LogKind.Frame, env.ItemId, env.FrameIndex, 0, now));
-        else if (env.FrameIndex == 0)
-            tx.InsertLog(channelId, new LogEntry(seq, LogKind.Announce, env.ItemId, 0, 0, now));
-
-        tx.UpdateItem(item with
-        {
-            FrameCount = item.FrameCount + 1,
-            MaxIndex = Math.Max(item.MaxIndex, env.FrameIndex),
-            FinalIndex = env.IsFinal ? env.FrameIndex : item.FinalIndex,
-            Bytes = item.Bytes + body.Length,
-        });
-        tx.AddChannelBytes(channelId, body.Length);
-        tx.TouchChannel(channelId, Math.Max(channel.ExpiresAt, now + ttlMs));
-
-        long lastSeq = seq;
-        var prefixes = new List<string>();
-
-        if (env.FrameIndex == 0)
-        {
-            // 新快照取代旧快照
-            if (env.IsSnapshot && tx.FindSnapshotItem(channelId, env.ItemId) is { } old)
-                lastSeq = DeleteItemCore(tx, channelId, old, TombstoneReason.Superseded, prefixes);
-
-            // 超出条数上限:淘汰最旧的条目
-            int excess = tx.CountItems(channelId) - channel.Settings.MaxItems;
-            if (excess > 0)
-            {
-                foreach (var victim in tx.ListOldestItems(channelId, excess + 1))
-                {
-                    if (excess <= 0) break;
-                    if (victim.ItemId == env.ItemId) continue;
-                    lastSeq = DeleteItemCore(tx, channelId, victim, TombstoneReason.Evicted, prefixes);
-                    excess--;
-                }
-            }
-
-            // 清理过期的墓碑,并推进续传水位
-            long pruned = tx.PruneTombstones(channelId, now - limits.TombstoneRetentionSeconds * 1000L);
-            if (pruned > channel.CompactedThrough) tx.SetCompactedThrough(channelId, pruned);
-        }
-
-        return new AppendOutcome(new AppendResult { Seq = seq, Created = true }, lastSeq, prefixes);
-    }
-
-    private static AppendResult Resolve(StoredFrame existing, byte[] digest) =>
-        existing.Digest.AsSpan().SequenceEqual(digest)
-            ? new AppendResult { Seq = existing.Seq, Created = false }
-            : throw new WebDropException(ErrorCode.Conflict);
-
-    private void ValidateShape(Envelope env)
-    {
-        if (env.IsControl && (env.IsGated || env.IsSnapshot || env.FrameIndex != 0 || !env.IsFinal || env.PayloadLength > 16_400)) throw new WebDropException(ErrorCode.BadRequest);
-        // 非 GATED 条目只能是单帧且必须 FINAL;快照只能是非 GATED 的单帧
-        if (!env.IsGated && (env.FrameIndex != 0 || !env.IsFinal)) throw new WebDropException(ErrorCode.BadRequest);
-        if (env.IsSnapshot && env.IsGated) throw new WebDropException(ErrorCode.BadRequest);
-    }
-
-    private static void CheckWritable(Channel channel, Principal principal, Envelope env)
-    {
-        if (!ChannelPolicy.CanWrite(channel, principal)) throw new WebDropException(ErrorCode.Forbidden);
-        if (env.IsEnc != (channel.Mode == ChannelMode.Enc)) throw new WebDropException(ErrorCode.ModeMismatch);
-        if (env.IsEnc && !PayloadTiers.IsValidEncPayloadLength(env.PayloadLength))
-            throw new WebDropException(ErrorCode.BadRequest);
-    }
-
-    private void DeleteBlobIfUnreferenced(string? blobKey)
-    {
-        if (blobKey is null) return;
-        if (!store.Read(tx => tx.BlobKeyExists(blobKey))) blobs.Delete(blobKey);
-    }
-
-    private static bool IsItemReadable(Item item, long now) =>
-        item.ExpiresAt > now && (item.CloseDeadline is null || item.CloseDeadline > now);
-
-    // ───────────────────────── 读取 ─────────────────────────
-
-    public async Task<LogPage> ReadLogAsync(Id16 id, Credentials creds, long from, int limit, CancellationToken ct = default)
-    {
-        limit = Math.Clamp(limit, 1, 1000);
-        var (pending, lastSeq) = store.Read(tx =>
-        {
-            var (channel, principal) = Authenticate(tx, id, creds, SeatRule.Required);
-            if (!ChannelPolicy.CanRead(principal)) throw new WebDropException(ErrorCode.Forbidden);
-
-            // 续传点早于已被清理的墓碑:客户端可能漏掉删除事件,必须从 0 全量同步
-            if (from > 0 && from < channel.CompactedThrough + 1)
-                throw new WebDropException(ErrorCode.Gone, channel.CompactedThrough + 1);
-
-            long now = clock.NowMs;
-            var list = new List<(long Seq, byte[]? Bytes, StoredFrame? Frame)>();
-            foreach (var e in tx.ReadLog(id, from, limit))
-            {
-                switch (e.Kind)
-                {
-                    case LogKind.Frame:
-                        if (tx.GetItem(id, e.ItemId) is { } frameItem && IsItemReadable(frameItem, now)
-                            && tx.GetFrame(id, e.ItemId, e.FrameIndex) is { } f)
-                            list.Add((e.Seq, null, f));
-                        break;
-                    case LogKind.Announce:
-                        if (tx.GetItem(id, e.ItemId) is { } it && IsItemReadable(it, now))
-                            list.Add((e.Seq, LogRecord.EncodeAnnounce(e.Seq, e.ItemId, it.Flags, it.CreatedAt), null));
-                        break;
-                    case LogKind.Tombstone:
-                        list.Add((e.Seq, LogRecord.EncodeTombstone(e.Seq, e.ItemId, (TombstoneReason)e.Aux), null));
-                        break;
-                }
-            }
-            return (list, channel.LastSeq);
-        });
-
-        var records = new List<LogRecord>(pending.Count);
-        foreach (var (seq, bytes, frame) in pending)
-        {
-            if (bytes is not null) { records.Add(new LogRecord(seq, bytes)); continue; }
-            byte[]? env = await LoadFrameBytesAsync(frame!, ct).ConfigureAwait(false);
-            if (env is not null) records.Add(new LogRecord(seq, LogRecord.Encode(seq, LogKind.Frame, env)));
-        }
-        return new LogPage(records, lastSeq);
-    }
-
-    /// <summary>开始拉取条目:鉴权,并按规则计一次下载。<paramref name="fromIndex"/> 为 0 才计数,大于 0 视为续传。</summary>
-    public void StartItemDownload(Id16 id, Credentials creds, Id16 itemId, uint fromIndex)
-    {
-        store.Write(tx =>
-        {
-            var (_, principal) = Authenticate(tx, id, creds, SeatRule.Required);
-            if (!ChannelPolicy.CanRead(principal)) throw new WebDropException(ErrorCode.Forbidden);
-            var item = tx.GetItem(id, itemId) ?? throw new WebDropException(ErrorCode.NotFound);
-
-            long now = clock.NowMs;
-            if (item.ExpiresAt <= now) throw new WebDropException(ErrorCode.Gone);
-            if (item.CloseDeadline is { } deadline && (fromIndex == 0 || now >= deadline))
-                throw new WebDropException(ErrorCode.Gone);
-            if (item.IsGated && fromIndex > 0 && !tx.HasDownloadGrant(id, itemId, principal.EndpointHash))
-                throw new WebDropException(ErrorCode.Gone);
-
-            if (fromIndex == 0 && item.IsGated)
-            {
-                if (item.MaxDownloads > 0 && item.Downloads >= item.MaxDownloads)
-                    throw new WebDropException(ErrorCode.Gone);
-
-                long downloads = item.Downloads + 1;
-                long? closeAt = item.MaxDownloads > 0 && downloads >= item.MaxDownloads
-                    ? now + limits.DownloadGraceSeconds * 1000L
-                    : item.CloseDeadline;
-                tx.UpdateItem(item with { Downloads = downloads, CloseDeadline = closeAt });
-                tx.AddDownloadGrant(id, itemId, principal.EndpointHash);
-            }
-            return 0;
-        });
-    }
-
-    /// <summary>读取自 <paramref name="fromIndex"/> 起连续的帧。条目未完成时可能返回空批次,调用方等待后重试。</summary>
-    public async Task<ItemChunk> ReadItemFramesAsync(
-        Id16 id, Credentials creds, Id16 itemId, uint fromIndex, int maxFrames, CancellationToken ct = default)
-    {
-        maxFrames = Math.Clamp(maxFrames, 1, 64);
-        var (frames, next, complete) = store.Read(tx =>
-        {
-            var (_, principal) = Authenticate(tx, id, creds, SeatRule.Required);
-            if (!ChannelPolicy.CanRead(principal)) throw new WebDropException(ErrorCode.Forbidden);
-            var item = tx.GetItem(id, itemId) ?? throw new WebDropException(ErrorCode.NotFound);
-            if (item.ExpiresAt <= clock.NowMs) throw new WebDropException(ErrorCode.Gone);
-            if (item.IsGated && !tx.HasDownloadGrant(id, itemId, principal.EndpointHash))
-                throw new WebDropException(ErrorCode.Gone);
-            if (item.CloseDeadline is { } d && clock.NowMs >= d) throw new WebDropException(ErrorCode.Gone);
-
-            var taken = new List<StoredFrame>();
-            uint expected = fromIndex;
-            foreach (var f in tx.ListFrames(id, itemId, fromIndex, maxFrames))
-            {
-                if (f.Index != expected) break; // 并行上传时可能有空洞
-                taken.Add(f);
-                expected++;
-            }
-            return (taken, expected, item.FinalIndex is { } fi && expected > fi);
-        });
-
-        var result = new List<byte[]>(frames.Count);
-        foreach (var f in frames)
-        {
-            byte[]? bytes = await LoadFrameBytesAsync(f, ct).ConfigureAwait(false);
-            if (bytes is null) throw new WebDropException(ErrorCode.Gone);
-            result.Add(bytes);
-        }
-        return new ItemChunk(result, next, complete);
-    }
-
-    private async ValueTask<byte[]?> LoadFrameBytesAsync(StoredFrame frame, CancellationToken ct) =>
-        frame.Inline ?? (frame.BlobKey is null ? null : await blobs.ReadAsync(frame.BlobKey, ct).ConfigureAwait(false));
-
-    // ───────────────────────── 删除 ─────────────────────────
-
-    public void DeleteItem(Id16 id, Credentials creds, Id16 itemId)
-    {
-        var (seq, prefixes) = store.Write(tx =>
-        {
-            var (channel, principal) = Authenticate(tx, id, creds, SeatRule.Required);
-            var item = tx.GetItem(id, itemId) ?? throw new WebDropException(ErrorCode.NotFound);
-            if (!ChannelPolicy.CanDeleteItem(channel, item, principal)) throw new WebDropException(ErrorCode.Forbidden);
-
-            var list = new List<string>();
-            long s = DeleteItemCore(tx, id, item, TombstoneReason.Deleted, list);
-            return (s, list);
-        });
-        foreach (string prefix in prefixes) blobs.DeletePrefix(prefix);
-        events.Advanced(id, seq);
-    }
-
-    private long DeleteItemCore(IResourceTx tx, Id16 channelId, Item item, TombstoneReason reason, List<string> prefixes)
-    {
-        tx.DeleteItemRows(channelId, item.ItemId);
-        tx.AddChannelBytes(channelId, -item.Bytes);
-        long seq = tx.NextSeq(channelId);
-        tx.InsertLog(channelId, new LogEntry(seq, LogKind.Tombstone, item.ItemId, 0, (byte)reason, clock.NowMs));
-        prefixes.Add($"{channelId.ToHex()}/{item.ItemId.ToHex()}");
-        return seq;
-    }
-
-    // ───────────────────────── 后台清理 ─────────────────────────
-
-    /// <summary>清理过期条目、下载达上限的条目、过期频道;可选清理孤立 blob。返回删除的条目和频道总数。</summary>
-    public int Sweep(bool includeOrphanBlobs = false)
-    {
-        int removed = 0;
-        long now = clock.NowMs;
-
-        foreach (var group in store.Read(tx => tx.ListExpiredItems(now, 500)).GroupBy(i => i.ChannelId))
-        {
-            var (lastSeq, prefixes, count) = store.Write(tx =>
-            {
-                long last = 0;
-                int n = 0;
-                var list = new List<string>();
-                foreach (var stale in group)
-                {
-                    // 重新读取,期间条目可能已被删除或续期
-                    if (tx.GetItem(stale.ChannelId, stale.ItemId) is not { } item) continue;
-                    bool closed = item.CloseDeadline is { } d && d <= now;
-                    if (item.ExpiresAt > now && !closed) continue;
-                    last = DeleteItemCore(tx, item.ChannelId, item, closed ? TombstoneReason.DownloadLimit : TombstoneReason.Expired, list);
-                    n++;
-                }
-                return (last, list, n);
-            });
-            foreach (string prefix in prefixes) blobs.DeletePrefix(prefix);
-            if (count > 0) events.Advanced(group.Key, lastSeq);
-            removed += count;
-        }
-
-        foreach (var channelId in store.Read(tx => tx.ListExpiredChannels(now, 200)))
-        {
-            bool deleted = store.Write(tx =>
-            {
-                if (tx.GetChannel(channelId) is not { } c || c.ExpiresAt > now) return false;
-                tx.DeleteChannelRows(channelId);
-                return true;
-            });
-            if (!deleted) continue;
-            blobs.DeletePrefix(channelId.ToHex());
-            events.ChannelDeleted(channelId);
-            removed++;
-        }
-
-        if (includeOrphanBlobs) SweepOrphanBlobs(now);
-        return removed;
-    }
-
-    /// <summary>删除没有任何帧引用、且超过 10 分钟的 blob(崩溃发生在写 blob 与提交事务之间会留下它们)。</summary>
-    private void SweepOrphanBlobs(long now)
-    {
-        var cutoff = DateTimeOffset.FromUnixTimeMilliseconds(now).AddMinutes(-10);
-        foreach (var (key, lastWrite) in blobs.Enumerate().ToList())
-        {
-            if (lastWrite > cutoff) continue;
-            if (!store.Read(tx => tx.BlobKeyExists(key))) blobs.Delete(key);
-        }
-    }
-
-    // ───────────────────────── 鉴权 ─────────────────────────
-
-    private (Channel Channel, Principal Principal) Authenticate(IResourceTx tx, Id16 id, Credentials creds, SeatRule seat)
-    {
-        var channel = tx.GetChannel(id);
-        if (channel is null || channel.ExpiresAt <= clock.NowMs) throw new WebDropException(ErrorCode.NotFound);
-
-        var role = VerifyRole(channel, creds);
-        var member = creds.AccountName is null ? null : tx.GetChannelMember(id, creds.AccountName);
-        if (role == Role.Owner && member?.Role != "owner") throw new WebDropException(ErrorCode.AccountRequired);
-        if (seat == SeatRule.Required)
-        {
-            var endpoint = tx.GetSeat(id, creds.EndpointHash);
-            if (endpoint is null) throw new WebDropException(ErrorCode.NotJoined);
-            if (endpoint.AccountName is not null && (endpoint.AccountName != creds.AccountName || member is null)) throw new WebDropException(ErrorCode.AccountRequired);
-            if (endpoint.AccountDeviceId is not null && endpoint.AccountDeviceId != creds.AccountDeviceId) throw new WebDropException(ErrorCode.AccountRequired);
-        }
-        return (channel, new Principal(role, creds.EndpointHash, creds.AccountName));
-    }
-
-    private static Role VerifyRole(Channel channel, Credentials creds)
-    {
-        switch (creds.ClaimedRole)
-        {
-            case Role.Read:
-                // raw 频道:知道 id 即可读;enc 频道必须出示读令牌
-                if (channel.Mode == ChannelMode.Raw) return Role.Read;
-                if (creds.Token is not null && TokenHash.Matches(creds.Token, channel.ReadHash)) return Role.Read;
-                break;
-            case Role.Write:
-                if (creds.Token is not null && TokenHash.Matches(creds.Token, channel.WriteHash)) return Role.Write;
-                break;
-            case Role.Owner:
-                if (creds.Token is not null && TokenHash.Matches(creds.Token, channel.OwnerHash)) return Role.Owner;
-                break;
-        }
-        throw new WebDropException(ErrorCode.Unauthorized);
-    }
-
-    private static void RequireOwner(Principal principal)
-    {
-        if (!ChannelPolicy.IsOwner(principal)) throw new WebDropException(ErrorCode.Forbidden);
-    }
-
-    private static ChannelInfo ToInfo(Channel channel, int seatsUsed) => new()
-    {
-        Id = channel.Id.ToBase64Url(),
-        CreatorAccount = channel.CreatorAccount,
-        PasswordRequired = channel.JoinPasswordHash is not null,
-        Mode = channel.Mode,
-        Settings = channel.Settings,
-        SeatsUsed = seatsUsed,
-        OldestSeq = channel.CompactedThrough + 1,
-        LastSeq = channel.LastSeq,
-        CreatedAt = channel.CreatedAt,
-        ExpiresAt = channel.ExpiresAt,
-    };
-}

server/src/WebDrop.Core/Channels/ChannelAdmission.cs

@@ -0,0 +1,111 @@
+using System.Security.Cryptography;
+
+namespace WebDrop.Core;
+
+public sealed partial class ChannelService
+{
+    private static (byte[]? Hash, byte[]? Salt) HashJoinPassword(string? password)
+    {
+        if (string.IsNullOrEmpty(password)) return (null, null);
+        if (password.Length is < 8 or > 256) throw new WebDropException(ErrorCode.BadRequest);
+        var salt = RandomNumberGenerator.GetBytes(16);
+        return (Rfc2898DeriveBytes.Pbkdf2(password, salt, 210_000, HashAlgorithmName.SHA256, 32), salt);
+    }
+
+    private static void CheckAdmission(IResourceTx tx, Channel channel, Credentials creds, string? password)
+    {
+        string account = creds.AccountName ?? throw new WebDropException(ErrorCode.AccountRequired);
+        if (account == channel.CreatorAccount) return;
+        if (tx.IsJoinDenied(channel.Id, account)) throw new WebDropException(ErrorCode.Forbidden);
+        if (tx.HasInvitation(channel.Id, account)) return;
+        if (tx.GetChannelMember(channel.Id, account) is not null) return;
+        if (channel.Settings.JoinPolicy == JoinPolicy.Invite) throw new WebDropException(ErrorCode.InvitationRequired);
+        if (channel.JoinPasswordHash is null) return;
+        if (string.IsNullOrEmpty(password)) throw new WebDropException(ErrorCode.ChannelPasswordRequired);
+        if (password.Length > 256) throw new WebDropException(ErrorCode.ChannelPasswordInvalid);
+        var actual = Rfc2898DeriveBytes.Pbkdf2(password, channel.JoinPasswordSalt!, 210_000, HashAlgorithmName.SHA256, 32);
+        if (!CryptographicOperations.FixedTimeEquals(actual, channel.JoinPasswordHash)) throw new WebDropException(ErrorCode.ChannelPasswordInvalid);
+    }
+
+    public IReadOnlyList<ChannelInvitation> Invitations(Id16 id, Credentials creds) => store.Read(tx =>
+    {
+        var (_, principal) = Authenticate(tx, id, creds, Membership.None);
+        if (!ChannelPolicy.IsOwner(principal)) RequireMemberPermission(tx, id, creds, WorkspacePermission.RemoveMembers);
+        return tx.ListInvitations(id);
+    });
+
+    /// <summary>成员列表,附带调用者能不能移除每一位(后端判断,前端只显示按钮)</summary>
+    public IReadOnlyList<MemberView> MembersView(Id16 id, Credentials creds) => store.Read(tx =>
+    {
+        var (_, principal) = Authenticate(tx, id, creds, Membership.None);
+        if (!ChannelPolicy.IsOwner(principal)) _ = Authenticate(tx, id, creds, Membership.Required);
+        var state = tx.GetWorkspace(id);
+        return tx.ListChannelMembers(id).Select(m => new MemberView(m, ChannelPolicy.CanRemoveMember(state, principal, m.Username, m.Role == "owner"))).ToList();
+    });
+
+    /// <summary>邀请列表,附带调用者能不能撤销每一条</summary>
+    public IReadOnlyList<InvitationView> InvitationsView(Id16 id, Credentials creds) => store.Read(tx =>
+    {
+        var (_, principal) = Authenticate(tx, id, creds, Membership.None);
+        if (!ChannelPolicy.IsOwner(principal)) principal = RequireMemberPermission(tx, id, creds, WorkspacePermission.RemoveMembers);
+        var state = tx.GetWorkspace(id);
+        return tx.ListInvitations(id).Select(i => new InvitationView(i, ChannelPolicy.CanRemoveMember(state, principal, i.Username, false))).ToList();
+    });
+
+    /// <summary>非空间主的调用方:必须是已加入的成员,且所在身份组被授予该权限</summary>
+    private Principal RequireMemberPermission(IResourceTx tx, Id16 id, Credentials creds, string permission)
+    {
+        var (_, principal) = Authenticate(tx, id, creds, Membership.Required);
+        if (!ChannelPolicy.HasPermission(tx.GetWorkspace(id), principal, permission)) throw new WebDropException(ErrorCode.Forbidden);
+        return principal;
+    }
+
+    public IReadOnlyList<ChannelInvitation> UserInvitations(string username) => store.Read(tx => tx.ListUserInvitations(username));
+
+    public void RevokeInvitation(Id16 id, Credentials creds, string username)
+    {
+        store.Write(tx =>
+        {
+            var (_, principal) = Authenticate(tx, id, creds, Membership.None);
+            bool targetIsOwner = tx.GetChannelMember(id, username)?.Role == "owner";
+            if (!ChannelPolicy.IsOwner(principal)) principal = RequireMemberPermission(tx, id, creds, WorkspacePermission.RemoveMembers);
+            if (!ChannelPolicy.CanRemoveMember(tx.GetWorkspace(id), principal, username, targetIsOwner)) throw new WebDropException(ErrorCode.Forbidden);
+            tx.DeleteInvitation(id, username);
+            tx.DeleteKeyPackage(id, username);
+            tx.DeleteChannelMember(id, username);
+            var crypto = tx.GetWorkspaceCrypto(id);
+            crypto.Access.RemoveAll(a => a.Username == username);
+            crypto.Envelopes.RemoveAll(e => e.Username == username);
+            crypto.Revision++;
+            tx.PutWorkspaceCrypto(id, crypto);
+            tx.DenyAccount(id, username);
+            return 0;
+        });
+        events.MembersChanged(id);
+    }
+
+    /// <summary>空间里所有成员的账号(不做鉴权,供已经通过鉴权的接口补全成员资料)</summary>
+    public IReadOnlyList<string> MemberAccounts(Id16 id) => store.Read(tx => tx.ListChannelMembers(id).Select(m => m.Username).ToList());
+
+    public IReadOnlyList<ChannelMember> Members(Id16 id, Credentials creds) => store.Read(tx =>
+    {
+        var (_, principal) = Authenticate(tx, id, creds, Membership.None);
+        if (!ChannelPolicy.IsOwner(principal)) _ = Authenticate(tx, id, creds, Membership.Required);
+        return tx.ListChannelMembers(id);
+    });
+
+    public IReadOnlyList<ChannelKeyPackage> AccountChannels(string username) =>
+        store.Read(tx => tx.ListUserKeyPackages(username, clock.NowMs));
+
+    public void SaveOwnerKeyPackage(Id16 id, Credentials creds, string payload)
+    {
+        if (payload is null || payload.Length is < 1 or > 16_384) throw new WebDropException(ErrorCode.BadRequest);
+        store.Write(tx =>
+        {
+            var (_, principal) = Authenticate(tx, id, creds, Membership.None);
+            RequireOwner(principal);
+            tx.PutKeyPackage(id, principal.AccountName!, payload, clock.NowMs);
+            return 0;
+        });
+    }
+}

server/src/WebDrop.Core/Channels/ChannelPolicy.cs

@@ -0,0 +1,103 @@
+namespace WebDrop.Core;
+
+/// <summary>谁能做什么。规则只写在这里,服务和测试都调用它。</summary>
+public static class ChannelPolicy
+{
+    public static bool IsOwner(Principal p) => p.Role == Role.Owner;
+
+    public static bool CanRead(Principal p) => p.Role >= Role.Read;
+
+    /// <summary>成员写入需要频道允许上传,且服务端持有写令牌哈希。</summary>
+    public static bool CanWrite(Channel channel, Principal p) =>
+        p.Role == Role.Owner
+        || (p.Role == Role.Write && channel.Settings.MembersCanUpload && channel.WriteHash is not null);
+
+    // ───── 空间所有者与频道访问授权(ChannelAccess):谁能读、写哪个频道的哪个数据域。其他地方只调用这里,不再各写一遍
+
+    /// <summary>空间的所有者:持有所有者令牌的人,或者空间的创建账号</summary>
+    public static bool IsSpaceOwner(Channel space, Principal p) => p.Role == Role.Owner || p.AccountName == space.CreatorAccount;
+
+    /// <summary>某个账号在某个频道上的访问授权;没有记录返回 null</summary>
+    public static ChannelAccess? AccessOf(CryptoState crypto, string? account, string channelId) =>
+        crypto.Access.Find(a => a.ChannelId == channelId && a.Username == account);
+
+    /// <summary>这条授权允许读这个数据域</summary>
+    public static bool CanReadDomain(ChannelAccess? access, CryptoDomain domain) =>
+        access is not null && (domain == CryptoDomain.Chat ? access.ChatRead : access.FilesRead);
+
+    /// <summary>这条授权允许写这个数据域(聊天域写消息,文件域上传)</summary>
+    public static bool CanWriteDomain(ChannelAccess? access, CryptoDomain domain) =>
+        access is not null && (domain == CryptoDomain.Chat ? access.ChatWrite : access.FilesUpload);
+
+    /// <summary>读一个对象:能读它所在的数据域,并且对象不早于授权生效的版本(关闭历史可读时,新成员看不到加入前的内容)</summary>
+    public static bool CanReadObject(ChannelAccess? access, CryptoDomain domain, long objectRevision) =>
+        CanReadDomain(access, domain) && objectRevision >= (domain == CryptoDomain.Chat ? access!.ChatFromRevision : access!.FilesFromRevision);
+
+    /// <summary>频道对这个账号可见:聊天或文件任一域能读</summary>
+    public static bool CanSeeChannel(ChannelAccess access) => access.ChatRead || access.FilesRead;
+
+    /// <summary>能碰这个频道的文件域:能读或能上传</summary>
+    public static bool CanUseFiles(ChannelAccess access) => access.FilesRead || access.FilesUpload;
+
+    /// <summary>能往频道里放东西:聊天或文件任一域能写</summary>
+    public static bool CanWriteAnyDomain(ChannelAccess? access) => access is not null && (access.ChatWrite || access.FilesUpload);
+
+    /// <summary>这个频道里能读某个数据域的账号</summary>
+    public static IEnumerable<ChannelAccess> Readers(CryptoState crypto, string channelId, CryptoDomain domain) =>
+        crypto.Access.Where(a => a.ChannelId == channelId && CanReadDomain(a, domain));
+
+    /// <summary>
+    /// 这个空间是否已经按授权记录来约束成员:加密空间有了密钥信封,明文空间有了授权记录或对象登记之后才约束。
+    /// 之前(刚建好、还没初始化)所有成员的行为和旧版一致。
+    /// </summary>
+    public static bool GrantsEnforced(Channel space, CryptoState crypto) =>
+        space.Mode == ChannelMode.Enc ? crypto.Envelopes.Count > 0 : crypto.Access.Count > 0 || crypto.Objects.Count > 0;
+
+    // ───── 空间权限(身份组授予)与结构管理
+
+    /// <summary>有没有这项空间权限:所有者拥有全部,其余看身份组授予</summary>
+    public static bool HasPermission(WorkspaceState? state, Principal principal, string permission) =>
+        principal.Role == Role.Owner
+        || principal.AccountName is { } account && state?.Roles.Any(r => r.Members.Contains(account) && r.Permissions.Contains(permission)) == true;
+
+    /// <summary>重命名频道、调整频道所属分组、管理分组(所有者,或被授予「管理频道和分组」)</summary>
+    public static bool CanManageStructure(WorkspaceState? state, Principal p) => HasPermission(state, p, WorkspacePermission.ManageStructure);
+
+    /// <summary>移除成员、撤销邀请的权限(所有者,或被授予「移除成员」)。具体能移除谁见 <see cref="CanRemoveMember"/></summary>
+    public static bool CanRemoveMembers(WorkspaceState? state, Principal p) => HasPermission(state, p, WorkspacePermission.RemoveMembers);
+
+    /// <summary>
+    /// 谁能移除谁:所有者能移除除自己外的任何人;被授权的成员不能移除自己、空间主,也不能移除同样有移除权限的人。
+    /// 执行(RevokeInvitation)和给前端的可移除标记(MembersView)都用这一处。
+    /// </summary>
+    public static bool CanRemoveMember(WorkspaceState? state, Principal acting, string target, bool targetIsOwner)
+    {
+        if (targetIsOwner) return false;
+        if (acting.Role == Role.Owner) return true;
+        return acting.AccountName is { } actor && actor != target
+            && CanRemoveMembers(state, acting)
+            && !CanRemoveMembers(state, new Principal(Role.Write, target));
+    }
+
+    // 下面这几项目前都只有所有者:新建频道(涉及密钥)、文件夹、邀请、改空间设置。要放开时只改这里
+
+    public static bool CanCreateChannel(Principal p) => IsOwner(p);
+    public static bool CanManageFolders(Principal p) => IsOwner(p);
+    public static bool CanInvite(Principal p) => IsOwner(p);
+    public static bool CanEditSettings(Principal p) => IsOwner(p);
+    public static bool CanManageRoles(Principal p) => IsOwner(p);
+
+    // ───── 删除条目
+
+    /// <summary>能删任何人发的条目:所有者,或空间的删除策略是 anyone</summary>
+    public static bool CanDeleteAnyItem(Channel channel, Principal p) =>
+        IsOwner(p) || p.Role >= Role.Read && channel.Settings.DeletePolicy == DeletePolicy.Anyone;
+
+    /// <summary>能删自己发的条目:所有者,或删除策略是 own / anyone</summary>
+    public static bool CanDeleteOwnItem(Channel channel, Principal p) =>
+        IsOwner(p) || p.Role >= Role.Read && channel.Settings.DeletePolicy is DeletePolicy.Own or DeletePolicy.Anyone;
+
+    /// <summary>某个具体条目能不能删:能删任何人的,或者是自己的并且能删自己的</summary>
+    public static bool CanDeleteItem(Channel channel, Item item, Principal p) =>
+        CanDeleteAnyItem(channel, p) || item.AuthorAccount == p.AccountName && CanDeleteOwnItem(channel, p);
+}

server/src/WebDrop.Core/Channels/ChannelService.cs

@@ -0,0 +1,875 @@
+using System.Security.Cryptography;
+using WebDrop.FileProtocol;
+
+namespace WebDrop.Core;
+
+/// <summary>
+/// 频道的全部业务逻辑。依赖抽象(存储、blob、时钟、事件),不含 HTTP、SQL、文件细节。
+/// 约定:所有失败以 <see cref="WebDropException"/> 表达;提交成功后才发事件;blob 先写后提交。
+/// </summary>
+public sealed partial class ChannelService(
+    IResourceStore store,
+    IBlobStore blobs,
+    IClock clock,
+    ServerLimits limits,
+    IChannelEvents events,
+    IFileGrants? fileGrants = null)
+{
+    private IFileGrants Files => fileGrants ?? NoFileGrants.Instance;
+    /// <summary>帧内容在文件域里的帧,BlobKey 以它开头;主后端只有头部、长度和摘要</summary>
+    public const string FilesPrefix = "files:";
+    /// <summary>这个条目是文件域的对象(不含目录控制帧)。所在频道没有分配文件域(文件服务没开、小文件)时,文件和聊天一样存在主后端</summary>
+    private static bool IsFileObject(IResourceTx tx, Id16 channelId, Envelope env) =>
+        !env.IsControl && FileDomainOf(tx, channelId, env.ItemId) is not null;
+
+    private static bool IsRemote(string? blobKey) => blobKey is not null && blobKey.StartsWith(FilesPrefix, StringComparison.Ordinal);
+
+    /// <summary>Required:必须已是频道成员;None:只验证身份(加入、查看信息等)。</summary>
+    private enum Membership { None, Required }
+
+    // ───────────────────────── 频道 ─────────────────────────
+
+    public ChannelInfo CreateChannel(CreateChannelRequest req, string creatorAccount)
+    {
+        if (string.IsNullOrWhiteSpace(creatorAccount)) throw new WebDropException(ErrorCode.AccountRequired);
+        if (req.KeyPackage is not null && req.KeyPackage.Length is < 1 or > 16_384) throw new WebDropException(ErrorCode.BadRequest);
+        if (!Id16.TryParse(req.Id, out var id)) throw new WebDropException(ErrorCode.BadRequest);
+        if (req.Mode is not { } mode) throw new WebDropException(ErrorCode.BadRequest);
+
+        var settings = req.Settings ?? CreationDefaults.Channel(limits);
+        if (string.IsNullOrWhiteSpace(settings.Name)) throw new WebDropException(ErrorCode.SpaceNameRequired);
+        settings.Name = settings.Name.Trim();
+        settings.Validate(limits);
+
+        if (!Codec.TryDecodeExact(req.OwnerHash, TokenHash.Size, out var ownerHash))
+            throw new WebDropException(ErrorCode.BadRequest);
+
+        byte[]? readHash = null;
+        if (mode == ChannelMode.Enc)
+        {
+            if (!Codec.TryDecodeExact(req.ReadHash, TokenHash.Size, out readHash))
+                throw new WebDropException(ErrorCode.BadRequest);
+        }
+        else if (req.ReadHash is not null)
+        {
+            throw new WebDropException(ErrorCode.BadRequest); // raw 频道的读权限是 id 本身
+        }
+
+        byte[]? writeHash = null;
+        if (req.WriteHash is not null && !Codec.TryDecodeExact(req.WriteHash, TokenHash.Size, out writeHash))
+            throw new WebDropException(ErrorCode.BadRequest);
+
+        long now = clock.NowMs;
+        var (passwordHash, passwordSalt) = HashJoinPassword(req.JoinPassword);
+        var channel = new Channel(id, mode, settings, readHash, writeHash, ownerHash,
+            now, now + settings.TtlSeconds * 1000L, 0, 0, 0, creatorAccount, passwordHash, passwordSalt);
+
+        store.Write(tx =>
+        {
+            if (tx.HasResourceId(id)) throw new WebDropException(ErrorCode.Conflict);
+            tx.InsertChannel(channel);
+            tx.PutWorkspace(id, NewWorkspace(creatorAccount, now));
+            tx.PutChannelMember(id, new ChannelMember(creatorAccount, "owner", now));
+            if (req.KeyPackage is not null) tx.PutKeyPackage(id, creatorAccount, req.KeyPackage, now);
+            return 0;
+        });
+        return ToInfo(channel, 1);
+    }
+
+    public ChannelInfo GetChannel(Id16 id, Credentials creds) => store.Read(tx =>
+    {
+        var (channel, principal) = Authenticate(tx, id, creds, Membership.None);
+        return ToInfo(channel, tx.CountMembers(id), principal, tx.GetChannelAvatarVersion(id), tx.GetWorkspace(id));
+    });
+
+    /// <summary>空间头像(thumb 为缩略图,否则原图)。需要能读这个空间</summary>
+    public AvatarBlob? GetChannelAvatarBlob(Id16 id, Credentials creds, bool thumb) => store.Read(tx =>
+    {
+        _ = Authenticate(tx, id, creds, Membership.None);
+        return tx.GetChannelAvatar(id, thumb);
+    });
+
+    public ChannelInfo UpdateSettings(Id16 id, Credentials creds, ChannelSettingsPatch patch)
+    {
+        var info = store.Write(tx =>
+        {
+            var (channel, principal) = Authenticate(tx, id, creds, Membership.None);
+            RequireOwner(principal);
+
+            var updated = patch.ApplyTo(channel.Settings);
+            updated.Validate(limits);
+            if (patch.Avatar is { Length: > 0 } newAvatar) AvatarData.Validate(newAvatar, AvatarData.MaxSpaceGifChars);
+            if (patch.AvatarThumb is { Length: > 0 } newThumb) { if (patch.Avatar is not { Length: > 0 }) throw new WebDropException(ErrorCode.BadRequest); AvatarData.ValidateThumb(newThumb); }
+            if (patch.Avatar is not null) tx.SetChannelAvatar(id, patch.Avatar.Length == 0 ? null : patch.Avatar, patch.Avatar.Length == 0 ? null : patch.AvatarThumb is { Length: > 0 } ? patch.AvatarThumb : null);
+
+            long expiresAt = updated.TtlSeconds != channel.Settings.TtlSeconds
+                ? clock.NowMs + updated.TtlSeconds * 1000L
+                : channel.ExpiresAt;
+            tx.UpdateChannel(id, updated, expiresAt);
+            if (patch.JoinPassword is not null)
+            {
+                var (hash, salt) = HashJoinPassword(patch.JoinPassword);
+                tx.SetJoinPassword(id, hash, salt);
+                channel = channel with { JoinPasswordHash = hash, JoinPasswordSalt = salt };
+            }
+            return ToInfo(channel with { Settings = updated, ExpiresAt = expiresAt }, tx.CountMembers(id), avatarVersion: tx.GetChannelAvatarVersion(id));
+        });
+        events.SettingsChanged(id);
+        return info;
+    }
+
+    public void DeleteChannel(Id16 id, Credentials creds)
+    {
+        store.Write(tx =>
+        {
+            var (_, principal) = Authenticate(tx, id, creds, Membership.None);
+            RequireOwner(principal);
+            tx.DeleteChannelRows(id);
+            return 0;
+        });
+        blobs.DeletePrefix(id.ToHex());
+        events.ChannelDeleted(id);
+    }
+
+    // ───────────────────────── 席位 ─────────────────────────
+
+    /// <summary>加入频道。只有已登录的账号能加入:登记成员关系,同一账号的多台设备不增加人数。</summary>
+    public JoinResult Join(Id16 id, Credentials creds, string? password = null)
+    {
+        var (joined, isNew) = store.Write(tx =>
+        {
+            var (channel, _) = Authenticate(tx, id, creds, Membership.None);
+            string account = creds.AccountName!;
+            int membersUsed = tx.CountMembers(id);
+            JoinResult Result(long joinedAt, int used) => new() { JoinedAt = joinedAt, MembersUsed = used, MembersMax = channel.Settings.MaxMembers };
+
+            if (tx.GetChannelMember(id, account) is { } existingMember) return (Result(existingMember.JoinedAt, membersUsed), false);
+            CheckAdmission(tx, channel, creds, password);
+            if (membersUsed >= channel.Settings.MaxMembers) throw new WebDropException(ErrorCode.MembersFull);
+            long memberAt = clock.NowMs;
+            tx.PutChannelMember(id, new ChannelMember(account, "member", memberAt));
+            return (Result(memberAt, membersUsed + 1), true);
+        });
+        if (isNew) events.MembersChanged(id);
+        return joined;
+    }
+
+    // ───────────────────────── 追加帧 ─────────────────────────
+
+    public async Task<AppendResult> AppendFrameAsync(
+        Id16 channelId, Credentials creds, ReadOnlyMemory<byte> body,
+        long? maxDownloads, CancellationToken ct = default, SignedContentEventProof? signedEvent = null)
+    {
+        if (!Envelope.TryParse(body.Span, out var env)) throw new WebDropException(ErrorCode.BadRequest);
+        if (env.PayloadLength > limits.MaxPayloadBytes) throw new WebDropException(ErrorCode.TooLarge);
+        ValidateShape(env);
+
+        byte[] digest = SHA256.HashData(body.Span);
+
+        // 1. 预检:鉴权并处理幂等重发,避免为重复帧白写 blob
+        var existing = store.Read(tx =>
+        {
+            var (channel, principal) = Authenticate(tx, channelId, creds, Membership.Required);
+            CheckWritable(channel, principal, env);
+            CheckObjectWrite(tx, channel, principal, env.ItemId);
+            // 文件域的对象不存主后端:字节在文件域里,主后端只在整个文件传完后一次登记头部和摘要(见 RegisterFileItem)
+            if (IsFileObject(tx, channelId, env)) throw new WebDropException(ErrorCode.UseFileApi);
+            return tx.GetFrame(channelId, env.ItemId, env.FrameIndex);
+        });
+        if (existing is not null) return Resolve(existing, digest);
+
+        // 2. 大帧先写 blob。键含摘要,内容不同的并发写不会互相覆盖
+        string? blobKey = null;
+        if (body.Length >= limits.InlineThresholdBytes)
+        {
+            blobKey = $"{channelId.ToHex()}/{env.ItemId.ToHex()}/{env.FrameIndex}.{Convert.ToHexStringLower(digest.AsSpan(0, 16))}";
+            await blobs.PutAsync(blobKey, body, ct).ConfigureAwait(false);
+        }
+
+        // 3. 单事务提交
+        AppendOutcome outcome;
+        try
+        {
+            outcome = store.Write(tx => AppendInTx(tx, channelId, creds, env, body, digest, blobKey, maxDownloads, signedEvent));
+        }
+        catch
+        {
+            DeleteBlobIfUnreferenced(blobKey);
+            throw;
+        }
+
+        if (!outcome.Result.Created) DeleteBlobIfUnreferenced(blobKey);
+        foreach (string prefix in outcome.BlobPrefixesToDelete) blobs.DeletePrefix(prefix);
+        events.Advanced(channelId, outcome.LastSeq);
+        if (outcome.NotifySettings) events.SettingsChanged(channelId);
+        return outcome.Result;
+    }
+
+    /// <summary>登记整个文件时,每一帧的负载长度和摘要(摘要是整帧封装的 SHA-256)</summary>
+    public readonly record struct FrameEntry(int PayloadLength, byte[] Digest);
+
+    /// <summary>
+    /// 一次登记整个文件:字节都在文件域里,逐帧登记要为每个 1 MiB 往返一次主后端,大文件的上传速度被它拖死。
+    /// 请求带的是末帧的头部和每一帧的(长度,摘要)。规则和逐帧登记完全一样:第 0 帧创建条目(含下载次数、日志里的公布),
+    /// 中间帧只落库,末帧验签名事件(清单摘要要和这里登记的所有摘要对得上)。整个登记在一个事务里,要么全成要么全不成。
+    /// 重复登记同一个文件(摘要全一致)幂等。
+    /// </summary>
+    public AppendResult RegisterFileItem(
+        Id16 channelId, Credentials creds, ReadOnlyMemory<byte> finalHeader, IReadOnlyList<FrameEntry> frames,
+        long? maxDownloads, SignedContentEventProof? signedEvent = null)
+    {
+        if (!Envelope.TryParseHeader(finalHeader.Span, out var last) || !last.IsFinal || frames.Count < 1
+            || last.FrameIndex != frames.Count - 1 || frames[^1].PayloadLength != last.PayloadLength) throw new WebDropException(ErrorCode.BadRequest);
+        if (frames.Count > limits.MaxFramesPerItem) throw new WebDropException(ErrorCode.TooLarge);
+        if (frames.Any(f => f.Digest.Length != 32 || f.PayloadLength < 0 || f.PayloadLength > limits.MaxPayloadBytes)) throw new WebDropException(ErrorCode.BadRequest);
+        // 每一帧的头部由末帧头部推出:条目级标志一致,只有末帧带 FINAL
+        FrameFlags itemFlags = last.Flags & ~FrameFlags.Final;
+        Envelope EnvelopeOf(int index) => new(index == frames.Count - 1 ? last.Flags : itemFlags, last.ItemId, (uint)index, frames[index].PayloadLength);
+        ValidateShape(EnvelopeOf(0)); ValidateShape(last);
+
+        var outcomes = store.Write<(AppendOutcome? First, AppendOutcome? Last, long Seq)>(tx =>
+        {
+            var (channel, principal) = Authenticate(tx, channelId, creds, Membership.Required);
+            for (int i = 0; i < frames.Count; i++) CheckWritable(channel, principal, EnvelopeOf(i));
+            CheckObjectWrite(tx, channel, principal, last.ItemId);
+            if (!IsFileObject(tx, channelId, last)) throw new WebDropException(ErrorCode.BadRequest);
+
+            // 已经登记过同一个文件:摘要全部一致就是重复请求,否则冲突
+            if (tx.GetItem(channelId, last.ItemId) is not null)
+            {
+                var stored = tx.ListFrames(channelId, last.ItemId, 0, limits.MaxFramesPerItem);
+                if (stored.Count != frames.Count || stored.Select((f, i) => f.Index == i && f.Digest.AsSpan().SequenceEqual(frames[i].Digest)).Any(same => !same))
+                    throw new WebDropException(ErrorCode.Conflict);
+                return (First: (AppendOutcome?)null, Last: (AppendOutcome?)null, Seq: stored[^1].Seq);
+            }
+            long middleBytes = 0;
+            for (int i = 1; i < frames.Count - 1; i++) middleBytes += EnvelopeOf(i).TotalLength;
+            if (channel.Bytes + middleBytes > limits.MaxWorkspaceBytes) throw new WebDropException(ErrorCode.TooLarge);
+
+            string BlobKeyOf(int i) => $"{FilesPrefix}{channelId.ToHex()}/{last.ItemId.ToHex()}/{i}";
+            var first = AppendInTx(tx, channelId, creds, EnvelopeOf(0), ReadOnlyMemory<byte>.Empty, frames[0].Digest, BlobKeyOf(0), maxDownloads,
+                frames.Count == 1 ? signedEvent : null);
+            if (frames.Count == 1) return (First: (AppendOutcome?)first, Last: null, Seq: first.LastSeq);
+
+            // 中间帧(受限条目的中间帧不进日志):只落库,条目计数一次性补上
+            for (int i = 1; i < frames.Count - 1; i++)
+            {
+                var env = EnvelopeOf(i);
+                tx.InsertFrame(new StoredFrame(channelId, last.ItemId, (uint)i, tx.NextSeq(channelId), env.TotalLength, frames[i].Digest, null, BlobKeyOf(i)));
+            }
+            if (frames.Count > 2)
+            {
+                var item = tx.GetItem(channelId, last.ItemId)!;
+                tx.UpdateItem(item with { FrameCount = item.FrameCount + frames.Count - 2, MaxIndex = Math.Max(item.MaxIndex, frames.Count - 2), Bytes = item.Bytes + middleBytes });
+                tx.AddChannelBytes(channelId, middleBytes);
+            }
+            var final = AppendInTx(tx, channelId, creds, last, ReadOnlyMemory<byte>.Empty, frames[^1].Digest, BlobKeyOf(frames.Count - 1), null, signedEvent);
+            return (First: (AppendOutcome?)first, Last: final, Seq: final.Result.Seq);
+        });
+
+        foreach (var outcome in new[] { outcomes.First, outcomes.Last })
+        {
+            if (outcome is null) continue;
+            foreach (string prefix in outcome.BlobPrefixesToDelete) blobs.DeletePrefix(prefix);
+            events.Advanced(channelId, outcome.LastSeq);
+            if (outcome.NotifySettings) events.SettingsChanged(channelId);
+        }
+        return new AppendResult { Seq = outcomes.Seq, Created = outcomes.First is not null };
+    }
+
+    /// <summary>条目所属频道的文件域(文件域的对象才有)</summary>
+    private static string? FileDomainOf(IResourceTx tx, Id16 spaceId, Id16 itemId)
+    {
+        var obj = tx.GetWorkspaceCrypto(spaceId).Objects.Find(o => o.ItemId == itemId.ToBase64Url() && o.Domain == CryptoDomain.Files);
+        return obj is null ? null : tx.GetWorkspace(spaceId)?.Channels.Find(c => c.Id == obj.ChannelId)?.FileDomain;
+    }
+
+    /// <summary>创建文件域的票据:只有空间所有者和有「管理频道和分组」权限的人能要。票据绑定空间 id</summary>
+    public FileGrant IssueCreateGrant(Id16 spaceId, Credentials creds)
+    {
+        if (!Files.Enabled) throw new WebDropException(ErrorCode.NotFound);
+        store.Read(tx =>
+        {
+            var (space, principal) = Authenticate(tx, spaceId, creds, Membership.Required);
+            if (!ChannelPolicy.CanManageStructure(tx.GetWorkspace(spaceId), principal)) throw new WebDropException(ErrorCode.Forbidden);
+            return 0;
+        });
+        return Files.Issue(FileOp.Create, spaceId.ToHex(), spaceId.ToHex(), "*", 0, clock.NowMs);
+    }
+
+    /// <summary>上传票据:确认能写这个条目所在的频道,然后给客户端文件域的访问凭证。</summary>
+    public FileGrant IssueUploadGrant(Id16 id, Credentials creds, Id16 itemId)
+    {
+        if (!Files.Enabled) throw new WebDropException(ErrorCode.NotFound);
+        string domain = store.Read(tx =>
+        {
+            var (space, principal) = Authenticate(tx, id, creds, Membership.Required);
+            if (!ChannelPolicy.CanWrite(space, principal)) throw new WebDropException(ErrorCode.Forbidden);
+            CheckObjectWrite(tx, space, principal, itemId);
+            return FileDomainOf(tx, id, itemId) ?? throw new WebDropException(ErrorCode.Conflict);
+        });
+        return Files.Issue(FileOp.Put, id.ToHex(), domain, itemId.ToHex(), 0, clock.NowMs);
+    }
+
+    /// <summary>
+    /// 文件域的查询票据(看容量和用量):能读这个频道的文件就行。票据的条目是 "*",只能查域,读不了任何文件。
+    /// </summary>
+    public FileGrant IssueDomainGrant(Id16 id, Credentials creds, string threadId)
+    {
+        if (!Files.Enabled) throw new WebDropException(ErrorCode.NotFound);
+        string domain = store.Read(tx =>
+        {
+            var (space, principal) = Authenticate(tx, id, creds, Membership.Required);
+            var workspace = tx.GetWorkspace(id) ?? throw new WebDropException(ErrorCode.NotFound);
+            var thread = workspace.Channels.Find(c => c.Id == threadId) ?? throw new WebDropException(ErrorCode.NotFound);
+            var crypto = tx.GetWorkspaceCrypto(id);
+            bool allowed = ChannelPolicy.IsSpaceOwner(space, principal)
+                || crypto.Access.Count == 0 && space.Mode == ChannelMode.Raw
+                || ChannelPolicy.AccessOf(crypto, principal.AccountName, threadId) is { } access && ChannelPolicy.CanUseFiles(access);
+            if (!allowed) throw new WebDropException(ErrorCode.Forbidden);
+            return thread.FileDomain ?? throw new WebDropException(ErrorCode.NotFound);
+        });
+        return Files.Issue(FileOp.Get, id.ToHex(), domain, "*", 0, clock.NowMs);
+    }
+
+    /// <summary>删除票据:确认调用者按原来的规则能删这个条目,再签。客户端先拿票据,再删主后端的条目,最后用票据清文件域里的字节</summary>
+    public FileGrant IssueDeleteGrant(Id16 id, Credentials creds, Id16 itemId)
+    {
+        if (!Files.Enabled) throw new WebDropException(ErrorCode.NotFound);
+        string domain = store.Read(tx =>
+        {
+            var (space, principal) = Authenticate(tx, id, creds, Membership.Required);
+            var item = tx.GetItem(id, itemId) ?? throw new WebDropException(ErrorCode.NotFound);
+            if (!ChannelPolicy.CanDeleteItem(space, item, principal)) throw new WebDropException(ErrorCode.Forbidden);
+            return FileDomainOf(tx, id, itemId) ?? throw new WebDropException(ErrorCode.NotFound);
+        });
+        return Files.Issue(FileOp.Delete, id.ToHex(), domain, itemId.ToHex(), 0, clock.NowMs);
+    }
+
+    /// <summary>
+    /// 下载票据:按原来的规则鉴权并计次(只有 from=0 才计),再签票据。条目没传完时返回冲突,让客户端稍后再来。
+    /// </summary>
+    public FileGrant IssueDownloadGrant(Id16 id, Credentials creds, Id16 itemId, uint fromIndex)
+    {
+        if (!Files.Enabled) throw new WebDropException(ErrorCode.NotFound);
+        string domain = store.Read(tx =>
+        {
+            var (space, principal) = Authenticate(tx, id, creds, Membership.Required);
+            if (!ChannelPolicy.CanRead(principal)) throw new WebDropException(ErrorCode.Forbidden);
+            var item = tx.GetItem(id, itemId) ?? throw new WebDropException(ErrorCode.NotFound);
+            if (!CanReadObject(tx, space, principal, itemId)) throw new WebDropException(ErrorCode.Forbidden);
+            if (item.FinalIndex is null) throw new WebDropException(ErrorCode.Conflict);
+            return FileDomainOf(tx, id, itemId) ?? throw new WebDropException(ErrorCode.NotFound);
+        });
+        StartItemDownload(id, creds, itemId, fromIndex, allowRemote: true);
+        return Files.Issue(FileOp.Get, id.ToHex(), domain, itemId.ToHex(), fromIndex, clock.NowMs);
+    }
+
+    private sealed class AppendOutcome(AppendResult result, long lastSeq, List<string> prefixes, bool notifySettings = false)
+    {
+        public AppendResult Result { get; } = result;
+        public long LastSeq { get; } = lastSeq;
+        public List<string> BlobPrefixesToDelete { get; } = prefixes;
+        public bool NotifySettings { get; } = notifySettings;
+    }
+
+    private AppendOutcome AppendInTx(
+        IResourceTx tx, Id16 channelId, Credentials creds, Envelope env, ReadOnlyMemory<byte> body,
+        byte[] digest, string? blobKey, long? maxDownloads, SignedContentEventProof? signedEvent)
+    {
+        var (channel, principal) = Authenticate(tx, channelId, creds, Membership.Required);
+        CheckWritable(channel, principal, env);
+        CheckObjectWrite(tx, channel, principal, env.ItemId);
+        int bodyLength = IsRemote(blobKey) ? env.TotalLength : body.Length;
+
+        // 并发下预检之后可能已有同一帧
+        if (tx.GetFrame(channelId, env.ItemId, env.FrameIndex) is { } dup)
+            return new AppendOutcome(Resolve(dup, digest), dup.Seq, []);
+
+        long now = clock.NowMs;
+        long ttlMs = channel.Settings.TtlSeconds * 1000L;
+        var item = tx.GetItem(channelId, env.ItemId);
+        var crypto = tx.GetWorkspaceCrypto(channelId);
+        var objectEnvelope = crypto.Objects.Find(o => o.ItemId == env.ItemId.ToBase64Url());
+        var workspaceState = objectEnvelope is null ? null : tx.GetWorkspace(channelId);
+        var workspaceChannel = objectEnvelope is null ? null : workspaceState?.Channels.Find(c => c.Id == objectEnvelope.ChannelId);
+        if (objectEnvelope is not null && workspaceChannel is null) throw new WebDropException(ErrorCode.BadRequest);
+        if (signedEvent is not null && (objectEnvelope is null || !env.IsFinal)) throw new WebDropException(ErrorCode.BadRequest);
+        if (objectEnvelope is not null && env.IsFinal)
+        {
+            if (signedEvent is null)
+            {
+                if (creds.RequireSignedContent) throw new WebDropException(ErrorCode.Forbidden);
+            }
+            else
+            {
+                if (objectEnvelope.AuthorAccount != principal.AccountName || signedEvent.Username != principal.AccountName || creds.AccountDeviceId != signedEvent.DeviceId
+                    || objectEnvelope.ChannelId != signedEvent.ChannelId || objectEnvelope.Domain != signedEvent.Domain
+                    || objectEnvelope.Epoch != signedEvent.Epoch || signedEvent.FrameCount != env.FrameIndex + 1
+                    || signedEvent.EventIdBytes.Length != 16 || signedEvent.ManifestHash.Length != 32 || signedEvent.Signature.Length != 64
+                    || objectEnvelope.Event is not null
+                    || signedEvent.Domain == CryptoDomain.Chat && signedEvent.EventKind is not ("chat.create" or "chat.edit" or "chat.snapshot")
+                    || signedEvent.Domain == CryptoDomain.Files && signedEvent.EventKind is not ("file.publish" or "file.catalog"))
+                    throw new WebDropException(ErrorCode.Forbidden);
+                if (signedEvent.EventKind == "chat.edit")
+                {
+                    if (signedEvent.TargetItemId is null || !Codec.TryDecodeExact(signedEvent.TargetItemId, 16, out var targetId)) throw new WebDropException(ErrorCode.BadRequest);
+                    var targetItem = tx.GetItem(channelId, Id16.FromBytes(targetId));
+                    var targetObject = crypto.Objects.Find(o => o.ItemId == signedEvent.TargetItemId);
+                    if (targetItem is null || targetObject?.Domain != CryptoDomain.Chat || !ChannelPolicy.CanDeleteItem(channel, targetItem, principal))
+                        throw new WebDropException(ErrorCode.Forbidden);
+                }
+                else if (signedEvent.TargetItemId is not null) throw new WebDropException(ErrorCode.BadRequest);
+                var manifestFrames = tx.ListFrames(channelId, env.ItemId, 0, limits.MaxFramesPerItem);
+                if (manifestFrames.Count != env.FrameIndex) throw new WebDropException(ErrorCode.Conflict);
+                var digests = new List<byte[]>(manifestFrames.Count + 1);
+                for (int i = 0; i < manifestFrames.Count; i++)
+                {
+                    if (manifestFrames[i].Index != i) throw new WebDropException(ErrorCode.Conflict);
+                    digests.Add(manifestFrames[i].Digest);
+                }
+                digests.Add(digest);
+                if (!CryptographicOperations.FixedTimeEquals(SignatureCodec.FrameManifestHash(digests), signedEvent.ManifestHash))
+                    throw new WebDropException(ErrorCode.Conflict);
+            }
+        }
+
+        if (env.FrameIndex == 0)
+        {
+            if (env.IsControl && tx.CountControlItems(channelId) >= 4096) throw new WebDropException(ErrorCode.TooLarge);
+            if (item is not null) throw new WebDropException(ErrorCode.BadRequest);
+            long max = env.IsGated ? maxDownloads ?? channel.Settings.FileMaxDownloads : 0;
+            if (env.IsGated && !ServerSettingChoices.IsFileMaxDownloadsAllowed(max, channel.Settings.FileMaxDownloads)) throw new WebDropException(ErrorCode.BadRequest);
+            item = new Item(channelId, env.ItemId, principal.GrantKey, env.ItemFlags, max, 0, 0, -1, null, 0,
+                now, env.IsControl ? long.MaxValue : now + ttlMs, null, principal.AccountName);
+            tx.InsertItem(item);
+        }
+        else
+        {
+            if (item is null) throw new WebDropException(ErrorCode.BadRequest);
+            if (item.Flags != env.ItemFlags) throw new WebDropException(ErrorCode.BadRequest);
+            if (item.CloseDeadline is not null) throw new WebDropException(ErrorCode.Gone);
+            if (item.FinalIndex is { } fi && env.FrameIndex > fi) throw new WebDropException(ErrorCode.BadRequest);
+        }
+
+        if (env.FrameIndex >= limits.MaxFramesPerItem) throw new WebDropException(ErrorCode.TooLarge);
+        if (env.IsFinal)
+        {
+            if (item.MaxIndex > env.FrameIndex) throw new WebDropException(ErrorCode.BadRequest);
+            if (item.FinalIndex is { } f && f != env.FrameIndex) throw new WebDropException(ErrorCode.BadRequest);
+        }
+        if (objectEnvelope is null && channel.Bytes + bodyLength > limits.MaxChannelBytes
+            || objectEnvelope is not null && channel.Bytes + bodyLength > limits.MaxWorkspaceBytes)
+            throw new WebDropException(ErrorCode.TooLarge);
+
+        long seq = tx.NextSeq(channelId);
+        tx.InsertFrame(new StoredFrame(channelId, env.ItemId, env.FrameIndex, seq, bodyLength, digest,
+            blobKey is null ? body.ToArray() : null, blobKey));
+
+        if (signedEvent is not null && objectEnvelope is not null)
+        {
+            objectEnvelope.Event = ToSignedContentEventRecord(signedEvent);
+            crypto.Revision++;
+            tx.PutWorkspaceCrypto(channelId, crypto);
+        }
+
+        // 受限帧和放在文件服务上的帧不进日志(日志里的帧自带内容),只在第 0 帧公布一次
+        if (!env.IsGated && !IsRemote(blobKey))
+            tx.InsertLog(channelId, new LogEntry(seq, LogKind.Frame, env.ItemId, env.FrameIndex, 0, now));
+        else if (env.FrameIndex == 0)
+            tx.InsertLog(channelId, new LogEntry(seq, LogKind.Announce, env.ItemId, 0, 0, now));
+
+        tx.UpdateItem(item with
+        {
+            FrameCount = item.FrameCount + 1,
+            MaxIndex = Math.Max(item.MaxIndex, env.FrameIndex),
+            FinalIndex = env.IsFinal ? env.FrameIndex : item.FinalIndex,
+            Bytes = item.Bytes + bodyLength,
+        });
+        tx.AddChannelBytes(channelId, bodyLength);
+        tx.TouchChannel(channelId, Math.Max(channel.ExpiresAt, now + ttlMs));
+
+        long lastSeq = seq;
+        var prefixes = new List<string>();
+
+        if (env.FrameIndex == 0)
+        {
+            // 新快照取代旧快照
+            if (env.IsSnapshot && tx.FindSnapshotItem(channelId, env.ItemId) is { } old)
+                lastSeq = DeleteItemCore(tx, channelId, old, TombstoneReason.Superseded, prefixes);
+
+            // 超出条数上限:淘汰最旧的条目
+            int excess = tx.CountItems(channelId) - channel.Settings.MaxItems;
+            if (excess > 0)
+            {
+                foreach (var victim in tx.ListOldestItems(channelId, excess + 1))
+                {
+                    if (excess <= 0) break;
+                    if (victim.ItemId == env.ItemId) continue;
+                    lastSeq = DeleteItemCore(tx, channelId, victim, TombstoneReason.Evicted, prefixes);
+                    excess--;
+                }
+            }
+
+            // 清理过期的墓碑,并推进续传水位
+            long pruned = tx.PruneTombstones(channelId, now - limits.TombstoneRetentionSeconds * 1000L);
+            if (pruned > channel.CompactedThrough) tx.SetCompactedThrough(channelId, pruned);
+        }
+
+        return new AppendOutcome(new AppendResult { Seq = seq, Created = true }, lastSeq, prefixes);
+    }
+
+    private static AppendResult Resolve(StoredFrame existing, byte[] digest) =>
+        existing.Digest.AsSpan().SequenceEqual(digest)
+            ? new AppendResult { Seq = existing.Seq, Created = false }
+            : throw new WebDropException(ErrorCode.Conflict);
+
+    private void ValidateShape(Envelope env)
+    {
+        if (env.IsControl && (env.IsGated || env.IsSnapshot || env.FrameIndex != 0 || !env.IsFinal || env.PayloadLength > 16_400)) throw new WebDropException(ErrorCode.BadRequest);
+        // 非 GATED 条目只能是单帧且必须 FINAL;快照只能是非 GATED 的单帧
+        if (!env.IsGated && (env.FrameIndex != 0 || !env.IsFinal)) throw new WebDropException(ErrorCode.BadRequest);
+        if (env.IsSnapshot && env.IsGated) throw new WebDropException(ErrorCode.BadRequest);
+    }
+
+    private static void CheckWritable(Channel channel, Principal principal, Envelope env)
+    {
+        if (!ChannelPolicy.CanWrite(channel, principal)) throw new WebDropException(ErrorCode.Forbidden);
+        if (env.IsEnc != (channel.Mode == ChannelMode.Enc)) throw new WebDropException(ErrorCode.ModeMismatch);
+        if (env.IsEnc && !PayloadTiers.IsValidEncPayloadLength(env.PayloadLength))
+            throw new WebDropException(ErrorCode.BadRequest);
+    }
+
+    private void DeleteBlobIfUnreferenced(string? blobKey)
+    {
+        if (blobKey is null) return;
+        if (!store.Read(tx => tx.BlobKeyExists(blobKey))) blobs.Delete(blobKey);
+    }
+
+    private static bool IsItemReadable(Item item, long now) =>
+        item.ExpiresAt > now && (item.CloseDeadline is null || item.CloseDeadline > now);
+
+    // ───────────────────────── 读取 ─────────────────────────
+
+    public async Task<LogPage> ReadLogAsync(Id16 id, Credentials creds, long from, int limit, CancellationToken ct = default)
+    {
+        limit = Math.Clamp(limit, 1, 1000);
+        var (pending, lastSeq) = store.Read(tx =>
+        {
+            var (channel, principal) = Authenticate(tx, id, creds, Membership.Required);
+            if (!ChannelPolicy.CanRead(principal)) throw new WebDropException(ErrorCode.Forbidden);
+
+            // 续传点早于已被清理的墓碑:客户端可能漏掉删除事件,必须从 0 全量同步
+            if (from > 0 && from < channel.CompactedThrough + 1)
+                throw new WebDropException(ErrorCode.Gone, channel.CompactedThrough + 1);
+
+            long now = clock.NowMs;
+            var list = new List<(long Seq, byte[]? Bytes, StoredFrame? Frame)>();
+            foreach (var e in tx.ReadLog(id, from, limit))
+            {
+                if (e.ItemId != default && !CanReadObject(tx, channel, principal, e.ItemId)) continue;
+                switch (e.Kind)
+                {
+                    case LogKind.Frame:
+                        if (tx.GetItem(id, e.ItemId) is { } frameItem && IsItemReadable(frameItem, now)
+                            && tx.GetFrame(id, e.ItemId, e.FrameIndex) is { } f)
+                            list.Add((e.Seq, null, f));
+                        break;
+                    case LogKind.Announce:
+                        if (tx.GetItem(id, e.ItemId) is { } it && IsItemReadable(it, now))
+                            list.Add((e.Seq, LogRecord.EncodeAnnounce(e.Seq, e.ItemId, it.Flags, it.CreatedAt), null));
+                        break;
+                    case LogKind.Tombstone:
+                        list.Add((e.Seq, LogRecord.EncodeTombstone(e.Seq, e.ItemId, (TombstoneReason)e.Aux), null));
+                        break;
+                }
+            }
+            return (list, channel.LastSeq);
+        });
+
+        var records = new List<LogRecord>(pending.Count);
+        foreach (var (seq, bytes, frame) in pending)
+        {
+            if (bytes is not null) { records.Add(new LogRecord(seq, bytes)); continue; }
+            byte[]? env = await LoadFrameBytesAsync(frame!, ct).ConfigureAwait(false);
+            if (env is not null) records.Add(new LogRecord(seq, LogRecord.Encode(seq, LogKind.Frame, env)));
+        }
+        return new LogPage(records, lastSeq);
+    }
+
+    /// <summary>开始拉取条目:鉴权,并按规则计一次下载。<paramref name="fromIndex"/> 为 0 才计数,大于 0 视为续传。</summary>
+    public void StartItemDownload(Id16 id, Credentials creds, Id16 itemId, uint fromIndex, bool allowRemote = false)
+    {
+        store.Write(tx =>
+        {
+            var (space, principal) = Authenticate(tx, id, creds, Membership.Required);
+            if (!ChannelPolicy.CanRead(principal)) throw new WebDropException(ErrorCode.Forbidden);
+            var item = tx.GetItem(id, itemId) ?? throw new WebDropException(ErrorCode.NotFound);
+            if (!CanReadObject(tx, space, principal, itemId)) throw new WebDropException(ErrorCode.Forbidden);
+            if (!allowRemote && IsRemote(tx.GetFrame(id, itemId, 0)?.BlobKey)) throw new WebDropException(ErrorCode.UseFileApi);
+
+            long now = clock.NowMs;
+            if (item.ExpiresAt <= now) throw new WebDropException(ErrorCode.Gone);
+            if (item.CloseDeadline is { } deadline && (fromIndex == 0 || now >= deadline))
+                throw new WebDropException(ErrorCode.Gone);
+            if (item.IsGated && fromIndex > 0 && !tx.HasDownloadGrant(id, itemId, principal.GrantKey))
+                throw new WebDropException(ErrorCode.Gone);
+
+            if (fromIndex == 0 && item.IsGated)
+            {
+                if (item.MaxDownloads > 0 && item.Downloads >= item.MaxDownloads)
+                    throw new WebDropException(ErrorCode.Gone);
+
+                long downloads = item.Downloads + 1;
+                long? closeAt = item.MaxDownloads > 0 && downloads >= item.MaxDownloads
+                    ? now + limits.DownloadGraceSeconds * 1000L
+                    : item.CloseDeadline;
+                tx.UpdateItem(item with { Downloads = downloads, CloseDeadline = closeAt });
+                tx.AddDownloadGrant(id, itemId, principal.GrantKey);
+            }
+            return 0;
+        });
+    }
+
+    /// <summary>读取自 <paramref name="fromIndex"/> 起连续的帧。条目未完成时可能返回空批次,调用方等待后重试。</summary>
+    public async Task<ItemChunk> ReadItemFramesAsync(
+        Id16 id, Credentials creds, Id16 itemId, uint fromIndex, int maxFrames, CancellationToken ct = default)
+    {
+        maxFrames = Math.Clamp(maxFrames, 1, 64);
+        var (frames, next, complete) = store.Read(tx =>
+        {
+            var (space, principal) = Authenticate(tx, id, creds, Membership.Required);
+            if (!ChannelPolicy.CanRead(principal)) throw new WebDropException(ErrorCode.Forbidden);
+            var item = tx.GetItem(id, itemId) ?? throw new WebDropException(ErrorCode.NotFound);
+            if (!CanReadObject(tx, space, principal, itemId)) throw new WebDropException(ErrorCode.Forbidden);
+            if (item.ExpiresAt <= clock.NowMs) throw new WebDropException(ErrorCode.Gone);
+            if (item.IsGated && !tx.HasDownloadGrant(id, itemId, principal.GrantKey))
+                throw new WebDropException(ErrorCode.Gone);
+            if (item.CloseDeadline is { } d && clock.NowMs >= d) throw new WebDropException(ErrorCode.Gone);
+
+            var taken = new List<StoredFrame>();
+            uint expected = fromIndex;
+            foreach (var f in tx.ListFrames(id, itemId, fromIndex, maxFrames))
+            {
+                if (f.Index != expected) break; // 并行上传时可能有空洞
+                taken.Add(f);
+                expected++;
+            }
+            return (taken, expected, item.FinalIndex is { } fi && expected > fi);
+        });
+
+        var result = new List<byte[]>(frames.Count);
+        foreach (var f in frames)
+        {
+            byte[]? bytes = await LoadFrameBytesAsync(f, ct).ConfigureAwait(false);
+            if (bytes is null) throw new WebDropException(ErrorCode.Gone);
+            result.Add(bytes);
+        }
+        return new ItemChunk(result, next, complete);
+    }
+
+    private async ValueTask<byte[]?> LoadFrameBytesAsync(StoredFrame frame, CancellationToken ct)
+    {
+        if (IsRemote(frame.BlobKey)) throw new WebDropException(ErrorCode.UseFileApi);
+        return frame.Inline ?? (frame.BlobKey is null ? null : await blobs.ReadAsync(frame.BlobKey, ct).ConfigureAwait(false));
+    }
+
+    // ───────────────────────── 删除 ─────────────────────────
+
+    public ObjectEnvelope? ObjectSigningContext(Id16 id, Credentials creds, Id16 itemId) => store.Read(tx =>
+    {
+        _ = Authenticate(tx, id, creds, Membership.Required);
+        return tx.GetWorkspaceCrypto(id).Objects.Find(o => o.ItemId == itemId.ToBase64Url());
+    });
+
+    public void DeleteItem(Id16 id, Credentials creds, Id16 itemId, SignedContentEventProof? signedEvent = null)
+    {
+        var (seq, prefixes) = store.Write(tx =>
+        {
+            var (channel, principal) = Authenticate(tx, id, creds, Membership.Required);
+            var item = tx.GetItem(id, itemId) ?? throw new WebDropException(ErrorCode.NotFound);
+            if (!ChannelPolicy.CanDeleteItem(channel, item, principal)) throw new WebDropException(ErrorCode.Forbidden);
+
+            var crypto = tx.GetWorkspaceCrypto(id);
+            var obj = crypto.Objects.Find(o => o.ItemId == itemId.ToBase64Url());
+            // 没传完的上传(末帧从未入库)没有已验签的清单,也就不可能有删除事件:作者或空间主可以直接清理,否则它会永久占着空间配额
+            bool unfinished = obj is not null && obj.Event is null;
+            if (creds.RequireSignedContent && obj is not null && !unfinished)
+            {
+                if (signedEvent is null || obj?.Event is null || signedEvent.Username != principal.AccountName
+                    || signedEvent.DeviceId != creds.AccountDeviceId || signedEvent.ChannelId != obj.ChannelId
+                    || signedEvent.Domain != obj.Domain || signedEvent.Epoch != obj.Epoch
+                    || signedEvent.FrameCount != obj.Event.FrameCount || signedEvent.ManifestHash.Length != 32
+                    || !Codec.TryDecodeExact(obj.Event.ManifestHash, 32, out var oldManifest)
+                    || !CryptographicOperations.FixedTimeEquals(signedEvent.ManifestHash, oldManifest)
+                    || signedEvent.EventKind != (obj.Domain == CryptoDomain.Chat ? "chat.delete" : "file.delete")
+                    || signedEvent.TargetItemId is not null || signedEvent.EventIdBytes.Length != 16 || signedEvent.Signature.Length != 64
+                    || obj.DeleteEvent is not null)
+                    throw new WebDropException(ErrorCode.Forbidden);
+                obj.DeleteEvent = ToSignedContentEventRecord(signedEvent);
+                crypto.Revision++;
+                tx.PutWorkspaceCrypto(id, crypto);
+            }
+            else if (signedEvent is not null) throw new WebDropException(ErrorCode.BadRequest);
+
+            var list = new List<string>();
+            long s = DeleteItemCore(tx, id, item, TombstoneReason.Deleted, list);
+            return (s, list);
+        });
+        foreach (string prefix in prefixes) blobs.DeletePrefix(prefix);
+        events.Advanced(id, seq);
+        events.SettingsChanged(id);
+    }
+
+    private long DeleteItemCore(IResourceTx tx, Id16 channelId, Item item, TombstoneReason reason, List<string> prefixes)
+    {
+        tx.DeleteItemRows(channelId, item.ItemId);
+        tx.AddChannelBytes(channelId, -item.Bytes);
+        long seq = tx.NextSeq(channelId);
+        tx.InsertLog(channelId, new LogEntry(seq, LogKind.Tombstone, item.ItemId, 0, (byte)reason, clock.NowMs));
+        prefixes.Add($"{channelId.ToHex()}/{item.ItemId.ToHex()}");
+        return seq;
+    }
+
+    private static SignedContentEventRecord ToSignedContentEventRecord(SignedContentEventProof signedEvent) => new()
+    {
+        EventId = Codec.Encode(signedEvent.EventIdBytes), Kind = signedEvent.EventKind, FrameCount = signedEvent.FrameCount,
+        ManifestHash = Convert.ToBase64String(signedEvent.ManifestHash).TrimEnd('=').Replace('+', '-').Replace('/', '_'),
+        SignerDeviceId = signedEvent.DeviceId, SignerAccount = signedEvent.Username,
+        Signature = Convert.ToBase64String(signedEvent.Signature).TrimEnd('=').Replace('+', '-').Replace('/', '_'),
+        TargetItemId = signedEvent.TargetItemId,
+        SignerRootPublicKey = signedEvent.RootPublicKey, SignerDevicePublicKey = signedEvent.DevicePublicKey,
+        DeviceCertificateSignature = Convert.ToBase64String(signedEvent.DeviceCertificateSignature).TrimEnd('=').Replace('+', '-').Replace('/', '_'),
+    };
+
+    // ───────────────────────── 后台清理 ─────────────────────────
+
+    /// <summary>清理过期条目、下载达上限的条目、过期频道;可选清理孤立 blob。返回删除的条目和频道总数。</summary>
+    public int Sweep(bool includeOrphanBlobs = false)
+    {
+        int removed = 0;
+        long now = clock.NowMs;
+
+        foreach (var group in store.Read(tx => tx.ListExpiredItems(now, 500)).GroupBy(i => i.ChannelId))
+        {
+            var (lastSeq, prefixes, count) = store.Write(tx =>
+            {
+                long last = 0;
+                int n = 0;
+                var list = new List<string>();
+                foreach (var stale in group)
+                {
+                    // 重新读取,期间条目可能已被删除或续期
+                    if (tx.GetItem(stale.ChannelId, stale.ItemId) is not { } item) continue;
+                    bool closed = item.CloseDeadline is { } d && d <= now;
+                    if (item.ExpiresAt > now && !closed) continue;
+                    last = DeleteItemCore(tx, item.ChannelId, item, closed ? TombstoneReason.DownloadLimit : TombstoneReason.Expired, list);
+                    n++;
+                }
+                return (last, list, n);
+            });
+            foreach (string prefix in prefixes) blobs.DeletePrefix(prefix);
+            if (count > 0) events.Advanced(group.Key, lastSeq);
+            removed += count;
+        }
+
+        foreach (var channelId in store.Read(tx => tx.ListExpiredChannels(now, 200)))
+        {
+            bool deleted = store.Write(tx =>
+            {
+                if (tx.GetChannel(channelId) is not { } c || c.ExpiresAt > now) return false;
+                tx.DeleteChannelRows(channelId);
+                return true;
+            });
+            if (!deleted) continue;
+            blobs.DeletePrefix(channelId.ToHex());
+            events.ChannelDeleted(channelId);
+            removed++;
+        }
+
+        if (includeOrphanBlobs) SweepOrphanBlobs(now);
+        return removed;
+    }
+
+    /// <summary>删除没有任何帧引用、且超过 10 分钟的 blob(崩溃发生在写 blob 与提交事务之间会留下它们)。</summary>
+    private void SweepOrphanBlobs(long now)
+    {
+        var cutoff = DateTimeOffset.FromUnixTimeMilliseconds(now).AddMinutes(-10);
+        foreach (var (key, lastWrite) in blobs.Enumerate().ToList())
+        {
+            if (lastWrite > cutoff) continue;
+            if (!store.Read(tx => tx.BlobKeyExists(key))) blobs.Delete(key);
+        }
+    }
+
+    // ───────────────────────── 鉴权 ─────────────────────────
+
+    private (Channel Channel, Principal Principal) Authenticate(IResourceTx tx, Id16 id, Credentials creds, Membership seat)
+    {
+        // 频道强制登录:没有账号会话的请求一律拒绝(便捷分享不受影响)
+        string account = creds.AccountName ?? throw new WebDropException(ErrorCode.AccountRequired);
+        var channel = tx.GetChannel(id);
+        if (channel is null || channel.ExpiresAt <= clock.NowMs) throw new WebDropException(ErrorCode.NotFound);
+
+        var role = VerifyRole(channel, creds);
+        var member = tx.GetChannelMember(id, account);
+        if (role == Role.Owner && member?.Role != "owner") throw new WebDropException(ErrorCode.AccountRequired);
+        if (seat == Membership.Required && member is null) throw new WebDropException(ErrorCode.NotJoined);
+        return (channel, new Principal(role, account));
+    }
+
+    private static Role VerifyRole(Channel channel, Credentials creds)
+    {
+        switch (creds.ClaimedRole)
+        {
+            case Role.Read:
+                // raw 频道:知道 id 即可读;enc 频道必须出示读令牌
+                if (channel.Mode == ChannelMode.Raw) return Role.Read;
+                if (creds.Token is not null && TokenHash.Matches(creds.Token, channel.ReadHash)) return Role.Read;
+                break;
+            case Role.Write:
+                if (creds.Token is not null && TokenHash.Matches(creds.Token, channel.WriteHash)) return Role.Write;
+                break;
+            case Role.Owner:
+                if (creds.Token is not null && TokenHash.Matches(creds.Token, channel.OwnerHash)) return Role.Owner;
+                break;
+        }
+        throw new WebDropException(ErrorCode.Unauthorized);
+    }
+
+    private static void RequireOwner(Principal principal)
+    {
+        if (!ChannelPolicy.IsOwner(principal)) throw new WebDropException(ErrorCode.Forbidden);
+    }
+
+    private static ChannelInfo ToInfo(Channel channel, int membersUsed, Principal? principal = null, string? avatarVersion = null, WorkspaceState? workspace = null)
+    {
+        // 没有调用者(创建、改设置时)就是所有者本人
+        var who = principal ?? new Principal(Role.Owner, channel.CreatorAccount);
+        return new()
+        {
+        AvatarVersion = avatarVersion,
+        IsOwner = ChannelPolicy.IsOwner(who),
+        CanUpload = ChannelPolicy.CanWrite(channel, who),
+        CanManageStructure = ChannelPolicy.CanManageStructure(workspace, who),
+        CanCreateChannel = ChannelPolicy.CanCreateChannel(who),
+        CanManageFolders = ChannelPolicy.CanManageFolders(who),
+        CanInvite = ChannelPolicy.CanInvite(who),
+        CanEditSettings = ChannelPolicy.CanEditSettings(who),
+        CanManageRoles = ChannelPolicy.CanManageRoles(who),
+        CanRemoveMembers = ChannelPolicy.CanRemoveMembers(workspace, who),
+        CanDeleteAny = ChannelPolicy.CanDeleteAnyItem(channel, who),
+        CanDeleteOwn = ChannelPolicy.CanDeleteOwnItem(channel, who),
+        Id = channel.Id.ToBase64Url(),
+        CreatorAccount = channel.CreatorAccount,
+        PasswordRequired = channel.JoinPasswordHash is not null,
+        Mode = channel.Mode,
+        Settings = channel.Settings,
+        MembersUsed = membersUsed,
+        OldestSeq = channel.CompactedThrough + 1,
+        LastSeq = channel.LastSeq,
+        CreatedAt = channel.CreatedAt,
+        ExpiresAt = channel.ExpiresAt,
+        };
+    }
+}

server/src/WebDrop.Core/Channels/Dtos.cs

@@ -52,12 +52,32 @@ public sealed class ShareItemInfo
 
 public sealed class ChannelInfo
 {
+    // ───── 调用者在这个空间里的能力。前端只读不算:规则只在后端一处
+    /// <summary>调用者是空间所有者</summary>
+    [JsonPropertyName("is_owner")] public bool IsOwner { get; init; }
+    [JsonPropertyName("can_upload")] public bool CanUpload { get; init; }
+    /// <summary>能重命名频道、管理分组(所有者,或被授予「管理频道和分组」)</summary>
+    [JsonPropertyName("can_manage_structure")] public bool CanManageStructure { get; init; }
+    [JsonPropertyName("can_create_channel")] public bool CanCreateChannel { get; init; }
+    [JsonPropertyName("can_manage_folders")] public bool CanManageFolders { get; init; }
+    [JsonPropertyName("can_invite")] public bool CanInvite { get; init; }
+    [JsonPropertyName("can_edit_settings")] public bool CanEditSettings { get; init; }
+    [JsonPropertyName("can_manage_roles")] public bool CanManageRoles { get; init; }
+    /// <summary>能移除成员、撤销邀请;具体能移除谁见成员列表里每一项的 can_remove</summary>
+    [JsonPropertyName("can_remove_members")] public bool CanRemoveMembers { get; init; }
+    /// <summary>能删除任何人的消息和文件(所有者,或删除策略为 anyone)</summary>
+    [JsonPropertyName("can_delete_any")] public bool CanDeleteAny { get; init; }
+    /// <summary>能删除自己发的消息和文件</summary>
+    [JsonPropertyName("can_delete_own")] public bool CanDeleteOwn { get; init; }
     [JsonPropertyName("password_required")] public bool PasswordRequired { get; init; }
     [JsonPropertyName("creator_account")] public string? CreatorAccount { get; init; }
+    /// <summary>头像版本标记,变了就要重新取头像(GET /channels/{id}/avatar);没有头像为 null。头像本体不随空间信息下发。</summary>
+    [JsonPropertyName("avatar_version")] public string? AvatarVersion { get; init; }
     [JsonPropertyName("id")] public required string Id { get; init; }
     [JsonPropertyName("mode")] public required ChannelMode Mode { get; init; }
     [JsonPropertyName("settings")] public required ChannelSettings Settings { get; init; }
-    [JsonPropertyName("seats_used")] public required int SeatsUsed { get; init; }
+    /// <summary>频道成员数(账号),不统计账号设备数。</summary>
+    [JsonPropertyName("members_used")] public required int MembersUsed { get; init; }
 
     /// <summary>从该 seq 起的续传有效;0 &lt; from &lt; oldest_seq 的续传会得到 410,需从 0 全量同步。</summary>
     [JsonPropertyName("oldest_seq")] public required long OldestSeq { get; init; }
@@ -67,20 +87,12 @@ public sealed class ChannelInfo
     [JsonPropertyName("expires_at")] public required long ExpiresAt { get; init; }
 }
 
-public sealed class SeatJoined
+public sealed class JoinResult
 {
-    [JsonPropertyName("endpoint_hash")] public required string EndpointHash { get; init; }
     [JsonPropertyName("joined_at")] public required long JoinedAt { get; init; }
-    [JsonPropertyName("seats_used")] public required int SeatsUsed { get; init; }
-    [JsonPropertyName("seats_max")] public required int SeatsMax { get; init; }
-}
-
-public sealed class SeatInfo
-{
-    [JsonPropertyName("account_name")] public string? AccountName { get; init; }
-    [JsonPropertyName("endpoint_hash")] public required string EndpointHash { get; init; }
-    [JsonPropertyName("joined_at")] public required long JoinedAt { get; init; }
-    [JsonPropertyName("label")] public string? Label { get; init; }
+    /// <summary>加入后的成员人数,同一账号的其他终端不增加此值。</summary>
+    [JsonPropertyName("members_used")] public required int MembersUsed { get; init; }
+    [JsonPropertyName("members_max")] public required int MembersMax { get; init; }
 }
 
 public sealed class AppendResult

server/src/WebDrop.Core/Channels/Settings.cs

@@ -8,22 +8,31 @@ public sealed class ServerLimits
     public int MaxPayloadBytes { get; set; } = (1 << 20) + 16;
     public int MaxFramesPerItem { get; set; } = 65_536;
     public long MaxChannelBytes { get; set; } = 1L << 30;
-    public int MaxSeats { get; set; } = 64;
+    public long MaxWorkspaceBytes { get; set; } = 1L << 40;
+    /// <summary>最大账号成员数。属性名和 info 字段保持旧线格式兼容。</summary>
+    public int MaxMembers { get; set; } = 64;
+    public int MaxVisitors { get; set; } = 10_000;
     public int MinTtlSeconds { get; set; } = 60;
     public int MaxTtlSeconds { get; set; } = 604_800;
     public int MaxItemsLimit { get; set; } = 10_000;
     public int InlineThresholdBytes { get; set; } = 64 * 1024;
     public int DownloadGraceSeconds { get; set; } = 300;
     public int TombstoneRetentionSeconds { get; set; } = 604_800;
-    public int MaxSeatLabelBytes { get; set; } = 256;
+}
+
+public static class ServerSettingChoices
+{
+    public static readonly int[] FileMaxDownloads = [0, 1, 3, 5, 10, 20];
+    public static bool IsFileMaxDownloadsAllowed(long value, int currentDefault) => value == currentDefault
+        || value is >= int.MinValue and <= int.MaxValue && Array.IndexOf(FileMaxDownloads, (int)value) >= 0;
 }
 
 public sealed class ChannelSettings
 {
-    [JsonPropertyName("join_policy")] public string JoinPolicy { get; set; } = "open";
-    [JsonPropertyName("allow_guests")] public bool AllowGuests { get; set; } = true;
+    [JsonPropertyName("join_policy")] public JoinPolicy JoinPolicy { get; set; } = JoinPolicy.Open;
     [JsonPropertyName("name")] public string? Name { get; set; }
-    [JsonPropertyName("seats")] public int Seats { get; set; } = 2;
+    /// <summary>成员人数上限;线字段名保留为 seats 以兼容已有频道设置。</summary>
+    [JsonPropertyName("max_members")] public int MaxMembers { get; set; } = 2;
     [JsonPropertyName("members_can_upload")] public bool MembersCanUpload { get; set; } = true;
     [JsonPropertyName("delete_policy")] public DeletePolicy DeletePolicy { get; set; } = DeletePolicy.Own;
     [JsonPropertyName("ttl_seconds")] public int TtlSeconds { get; set; } = 86_400;
@@ -33,9 +42,9 @@ public sealed class ChannelSettings
 
     public void Validate(ServerLimits limits)
     {
-        if (JoinPolicy is not ("open" or "invite")) throw new WebDropException(ErrorCode.BadRequest);
+        if (!Enum.IsDefined(JoinPolicy)) throw new WebDropException(ErrorCode.BadRequest);
         if (Name is { } name && (name.Length > 48 || name.Any(char.IsControl))) throw new WebDropException(ErrorCode.BadRequest);
-        if (Seats < 1 || Seats > limits.MaxSeats) throw new WebDropException(ErrorCode.BadRequest);
+        if (MaxMembers < 1 || MaxMembers > limits.MaxMembers) throw new WebDropException(ErrorCode.BadRequest);
         if (TtlSeconds < limits.MinTtlSeconds || TtlSeconds > limits.MaxTtlSeconds) throw new WebDropException(ErrorCode.BadRequest);
         if (MaxItems < 1 || MaxItems > limits.MaxItemsLimit) throw new WebDropException(ErrorCode.BadRequest);
         if (FileMaxDownloads < 0) throw new WebDropException(ErrorCode.BadRequest);
@@ -44,24 +53,26 @@ public sealed class ChannelSettings
 
 public sealed class ChannelSettingsPatch
 {
-    [JsonPropertyName("join_policy")] public string? JoinPolicy { get; init; }
-    [JsonPropertyName("allow_guests")] public bool? AllowGuests { get; init; }
+    [JsonPropertyName("join_policy")] public JoinPolicy? JoinPolicy { get; init; }
     [JsonPropertyName("join_password")] public string? JoinPassword { get; init; }
     [JsonPropertyName("name")] public string? Name { get; init; }
-    [JsonPropertyName("seats")] public int? Seats { get; init; }
+    [JsonPropertyName("max_members")] public int? MaxMembers { get; init; }
     [JsonPropertyName("members_can_upload")] public bool? MembersCanUpload { get; init; }
     [JsonPropertyName("delete_policy")] public DeletePolicy? DeletePolicy { get; init; }
     [JsonPropertyName("ttl_seconds")] public int? TtlSeconds { get; init; }
     [JsonPropertyName("max_items")] public int? MaxItems { get; init; }
     [JsonPropertyName("file_max_downloads")] public int? FileMaxDownloads { get; init; }
     [JsonPropertyName("ui_restrict_copy_download")] public bool? UiRestrictCopyDownload { get; init; }
+    /// <summary>空间头像 data URL;不传表示不改,空字符串表示移除。只有空间主能改。</summary>
+    [JsonPropertyName("avatar")] public string? Avatar { get; init; }
+    /// <summary>空间头像的有损小图(data URL):空间列表、标题默认只分发它,原图在预览时才下载</summary>
+    [JsonPropertyName("avatar_thumb")] public string? AvatarThumb { get; init; }
 
     public ChannelSettings ApplyTo(ChannelSettings s) => new()
     {
         JoinPolicy = JoinPolicy ?? s.JoinPolicy,
-        AllowGuests = AllowGuests ?? s.AllowGuests,
         Name = Name is null ? s.Name : string.IsNullOrWhiteSpace(Name) ? null : Name.Trim(),
-        Seats = Seats ?? s.Seats,
+        MaxMembers = MaxMembers ?? s.MaxMembers,
         MembersCanUpload = MembersCanUpload ?? s.MembersCanUpload,
         DeletePolicy = DeletePolicy ?? s.DeletePolicy,
         TtlSeconds = TtlSeconds ?? s.TtlSeconds,
@@ -80,7 +91,7 @@ public sealed class ShareSettings
     public void Validate(ServerLimits limits)
     {
         if (TtlSeconds < limits.MinTtlSeconds || TtlSeconds > limits.MaxTtlSeconds
-            || MaxVisitors < 0 || MaxVisitors > 10_000
+            || MaxVisitors < 0 || MaxVisitors > limits.MaxVisitors
             || FileMaxDownloads < 0)
             throw new WebDropException(ErrorCode.BadRequest);
     }
@@ -99,3 +110,22 @@ public sealed class ShareSettingsPatch
         FileMaxDownloads = FileMaxDownloads ?? s.FileMaxDownloads,
     };
 }
+
+/// <summary>创建接口与 /info 使用同一个配置来源；旧存储对象的字段默认值不作迁移。</summary>
+public static class CreationDefaults
+{
+    public const ChannelMode ChannelMode = WebDrop.Core.ChannelMode.Enc;
+
+    public static ChannelSettings Channel(ServerLimits limits) => new()
+    {
+        JoinPolicy = JoinPolicy.Invite,
+        MaxMembers = Math.Min(10, limits.MaxMembers),
+        TtlSeconds = Math.Clamp(86_400, limits.MinTtlSeconds, limits.MaxTtlSeconds),
+        MaxItems = Math.Min(1000, limits.MaxItemsLimit),
+    };
+    public static ShareSettings Share(ServerLimits limits) => new()
+    {
+        TtlSeconds = Math.Clamp(86_400, limits.MinTtlSeconds, limits.MaxTtlSeconds),
+        MaxVisitors = Math.Min(10, limits.MaxVisitors),
+    };
+}

server/src/WebDrop.Core/Common/Enums.cs

@@ -9,6 +9,20 @@ public enum ChannelMode : byte
     [JsonStringEnumMemberName("raw")] Raw = 2,
 }
 
+[JsonConverter(typeof(JsonStringEnumConverter<CryptoDomain>))]
+public enum CryptoDomain : byte
+{
+    [JsonStringEnumMemberName("chat")] Chat = 1,
+    [JsonStringEnumMemberName("files")] Files = 2,
+}
+
+[JsonConverter(typeof(JsonStringEnumConverter<JoinPolicy>))]
+public enum JoinPolicy : byte
+{
+    [JsonStringEnumMemberName("open")] Open = 1,
+    [JsonStringEnumMemberName("invite")] Invite = 2,
+}
+
 [JsonConverter(typeof(JsonStringEnumConverter<DeletePolicy>))]
 public enum DeletePolicy : byte
 {
@@ -52,3 +66,10 @@ public enum TombstoneReason : byte
     DownloadLimit = 3,
     Superseded = 4,
 }
+
+/// <summary>便捷分享的状态(线格式的取值)。前端从生成的契约里取,不手写字符串</summary>
+public static class ShareState
+{
+    public const string Draft = "draft";
+    public const string Sealed = "sealed";
+}

server/src/WebDrop.Core/Common/Envelope.cs

@@ -30,6 +30,18 @@ public readonly record struct Envelope(FrameFlags Flags, Id16 ItemId, uint Frame
         return true;
     }
 
+    /// <summary>只有 26 字节头部(不带负载)的帧:文件服务存负载,主后端只收头部和回执。长度字段仍要合法。</summary>
+    public static bool TryParseHeader(ReadOnlySpan<byte> data, out Envelope envelope)
+    {
+        envelope = default;
+        if (data.Length != HeaderSize || data[0] != Version) return false;
+        if ((data[1] & 0xE0) != 0) return false;
+        uint payloadLen = BinaryPrimitives.ReadUInt32BigEndian(data[22..]);
+        if (payloadLen > int.MaxValue) return false;
+        envelope = new Envelope((FrameFlags)data[1], Id16.FromBytes(data.Slice(2, Id16.Size)), BinaryPrimitives.ReadUInt32BigEndian(data[18..]), (int)payloadLen);
+        return true;
+    }
+
     public bool IsFinal => (Flags & FrameFlags.Final) != 0;
     public bool IsGated => (Flags & FrameFlags.Gated) != 0;
     public bool IsSnapshot => (Flags & FrameFlags.Snapshot) != 0;

server/src/WebDrop.Core/Common/Errors.cs

@@ -6,7 +6,7 @@ public enum ErrorCode
     Unauthorized,
     Forbidden,
     NotJoined,
-    SeatsFull,
+    MembersFull,
     ModeMismatch,
     NotFound,
     Conflict,
@@ -21,6 +21,11 @@ public enum ErrorCode
     InvitationRequired,
     ChannelPasswordRequired,
     ChannelPasswordInvalid,
+    SpaceNameRequired,
+    /// <summary>这个条目的内容在文件服务上:去要一张票据,直接找文件服务</summary>
+    UseFileApi,
+    /// <summary>文件服务暂时连不上或已满</summary>
+    FilesUnavailable,
 }
 
 /// <summary>预期内的业务失败。消息只含错误码,绝不回显用户提交的内容。</summary>
@@ -46,7 +51,7 @@ public static class ErrorCodes
         ErrorCode.Unauthorized => "unauthorized",
         ErrorCode.Forbidden => "forbidden",
         ErrorCode.NotJoined => "not_joined",
-        ErrorCode.SeatsFull => "seats_full",
+        ErrorCode.MembersFull => "members_full",
         ErrorCode.ModeMismatch => "mode_mismatch",
         ErrorCode.NotFound => "not_found",
         ErrorCode.Conflict => "conflict",
@@ -61,6 +66,9 @@ public static class ErrorCodes
         ErrorCode.InvitationRequired => "invitation_required",
         ErrorCode.ChannelPasswordRequired => "channel_password_required",
         ErrorCode.ChannelPasswordInvalid => "channel_password_invalid",
+        ErrorCode.SpaceNameRequired => "space_name_required",
+        ErrorCode.UseFileApi => "use_file_api",
+        ErrorCode.FilesUnavailable => "files_unavailable",
         _ => "bad_request",
     };
 
@@ -68,14 +76,17 @@ public static class ErrorCodes
     {
         ErrorCode.BadRequest => 400,
         ErrorCode.Unauthorized => 401,
-        ErrorCode.Forbidden or ErrorCode.NotJoined or ErrorCode.SeatsFull or ErrorCode.ModeMismatch => 403,
+        ErrorCode.Forbidden or ErrorCode.NotJoined or ErrorCode.MembersFull or ErrorCode.ModeMismatch => 403,
         ErrorCode.NotFound => 404,
         ErrorCode.Conflict => 409,
         ErrorCode.Sealed => 409,
+        ErrorCode.SpaceNameRequired => 400,
         ErrorCode.Gone => 410,
         ErrorCode.TooLarge => 413,
         ErrorCode.CaptchaRequired => 428,
         ErrorCode.CaptchaUnavailable => 503,
+        ErrorCode.FilesUnavailable => 503,
+        ErrorCode.UseFileApi => 409,
         ErrorCode.RateLimited => 429,
         ErrorCode.VisitorsFull => 403,
         ErrorCode.AccountRequired => 401,

server/src/WebDrop.Core/Common/Id16.cs

@@ -25,6 +25,15 @@ public readonly struct Id16 : IEquatable<Id16>
     }
 
     /// <summary>只接受规范的 22 字符 base64url,拒绝同一值的非规范编码。</summary>
+    /// <summary>32 个十六进制字符(文件服务和 blob 键里的写法)</summary>
+    public static bool TryParseHex(string? hex, out Id16 id)
+    {
+        id = default;
+        if (hex is not { Length: 32 }) return false;
+        try { id = FromBytes(Convert.FromHexString(hex)); return true; }
+        catch (FormatException) { return false; }
+    }
+
     public static bool TryParse(ReadOnlySpan<char> text, out Id16 id)
     {
         id = default;

server/src/WebDrop.Core/Common/Models.cs

@@ -82,9 +82,10 @@ public sealed record Item(
     public bool IsComplete => FinalIndex is { } f && FrameCount == f + 1;
 }
 
-public sealed record Seat(byte[] EndpointHash, long JoinedAt, byte[]? Label, string? AccountName = null, string? AccountDeviceId = null);
 public sealed record ChannelInvitation(Id16 ChannelId, string Username, string Payload, long CreatedAt);
 public sealed record ChannelMember(string Username, string Role, long JoinedAt);
+public sealed record MemberView(ChannelMember Member, bool CanRemove);
+public sealed record InvitationView(ChannelInvitation Invitation, bool CanRevoke);
 public sealed record ChannelKeyPackage(Id16 ChannelId, string Username, string Role, string Payload, long CreatedAt);
 
 /// <summary>已存储的一帧(完整封装)。Inline 与 BlobKey 二选一。</summary>
@@ -100,8 +101,13 @@ public sealed record StoredFrame(
 
 public sealed record LogEntry(long Seq, LogKind Kind, Id16 ItemId, uint FrameIndex, byte Aux, long CreatedAt);
 
-/// <summary>一次请求验证通过后的身份。</summary>
-public sealed record Principal(Role Role, byte[] EndpointHash, string? AccountName = null);
+/// <summary>一次请求验证通过后的身份。频道只接受已登录账号。</summary>
+public sealed record Principal(Role Role, string AccountName)
+{
+    /// <summary>受限下载的计数单位:按用户计(设备只是账号的属性)。</summary>
+    public byte[] GrantKey => System.Security.Cryptography.SHA256.HashData(System.Text.Encoding.UTF8.GetBytes("webdrop/grant/v1/" + AccountName));
+}
 
 /// <summary>请求携带的凭据,尚未验证。</summary>
-public sealed record Credentials(Role ClaimedRole, byte[]? Token, byte[] EndpointHash, string? AccountName = null, string? AccountDeviceId = null);
+public sealed record Credentials(Role ClaimedRole, byte[]? Token, byte[] EndpointHash, string? AccountName = null, string? AccountDeviceId = null,
+    bool RequireSignedContent = false);

server/src/WebDrop.Core/Files/IFileGrants.cs

@@ -0,0 +1,27 @@
+using WebDrop.FileProtocol;
+
+namespace WebDrop.Core;
+
+/// <summary>给客户端的访问凭证:文件服务地址、文件域 id 和一张短期票据</summary>
+public sealed record FileGrant(string Url, string Domain, string Ticket, long ExpiresAt);
+
+/// <summary>
+/// 主后端只负责「权限」:判断某人在某个空间里能不能读写某个频道的文件,然后给文件服务(fileAPI)签一张短期票据。
+/// 文件域的创建、容量、用量、字节的存取都是文件服务自己的事,主后端既不调用它,也不保存它的任何状态。
+/// </summary>
+public interface IFileGrants
+{
+    bool Enabled { get; }
+    /// <summary>文件服务对外的地址,告诉客户端去哪里</summary>
+    string PublicUrl { get; }
+    /// <summary>space:签发票据的空间 id(十六进制)。scope:Create 时是空间 id;其余是文件域 id。item 是条目 id(十六进制)或 "*"</summary>
+    FileGrant Issue(FileOp op, string space, string scope, string item, uint from, long nowMs);
+}
+
+public sealed class NoFileGrants : IFileGrants
+{
+    public static readonly NoFileGrants Instance = new();
+    public bool Enabled => false;
+    public string PublicUrl => "";
+    public FileGrant Issue(FileOp op, string space, string scope, string item, uint from, long nowMs) => throw new WebDropException(ErrorCode.NotFound);
+}

server/src/WebDrop.Core/Shares/ShareService.cs

@@ -18,7 +18,7 @@ public sealed class ShareService(
             || !Codec.TryDecodeExact(req.OwnerHash, TokenHash.Size, out var ownerHash))
             throw new WebDropException(ErrorCode.BadRequest);
 
-        var settings = req.Settings ?? new ShareSettings();
+        var settings = req.Settings ?? CreationDefaults.Share(limits);
         settings.Validate(limits);
         long now = clock.NowMs;
         var share = new Share(id, settings, readHash, ownerHash, creatorEndpointHash, now,
@@ -102,6 +102,7 @@ public sealed class ShareService(
                     if (item is not null) throw new WebDropException(ErrorCode.BadRequest);
                     if (tx.CountShareItems(id) >= limits.MaxItemsLimit) throw new WebDropException(ErrorCode.TooLarge);
                     long cap = env.IsGated ? maxDownloads ?? share.Settings.FileMaxDownloads : 0;
+                    if (env.IsGated && !ServerSettingChoices.IsFileMaxDownloadsAllowed(cap, share.Settings.FileMaxDownloads)) throw new WebDropException(ErrorCode.BadRequest);
                     item = new ShareItem(id, env.ItemId, env.ItemFlags, cap, 0, 0, -1, null,
                         0, now, share.ExpiresAt, null);
                     tx.InsertShareItem(item);
@@ -354,7 +355,7 @@ public sealed class ShareService(
     private static ShareInfo ToInfo(Share share, IReadOnlyList<ShareItem> items) => new()
     {
         Id = share.Id.ToBase64Url(),
-        State = share.IsSealed ? "sealed" : "draft",
+        State = share.IsSealed ? ShareState.Sealed : ShareState.Draft,
         ExpiresAt = share.ExpiresAt,
         CreatedAt = share.CreatedAt,
         SealedAt = share.SealedAt,

server/src/WebDrop.Core/Spaces/ChannelCrypto.cs

@@ -0,0 +1,205 @@
+namespace WebDrop.Core;
+
+public sealed partial class ChannelService
+{
+    public InvitationCryptoPlan InvitationPlan(Id16 id, Credentials creds, string username) => store.Read(tx =>
+    {
+        var (space, principal) = Authenticate(tx, id, creds, Membership.None); RequireOwner(principal);
+        if (tx.GetChannelMember(id, username) is not null || tx.HasInvitation(id, username)) throw new WebDropException(ErrorCode.Conflict);
+        var workspace = tx.GetWorkspace(id) ?? throw new WebDropException(ErrorCode.NotFound);
+        var channelId = workspace.DefaultChannelId ?? throw new WebDropException(ErrorCode.Conflict);
+        var channel = workspace.Channels.Find(c => c.Id == channelId) ?? throw new WebDropException(ErrorCode.Conflict);
+        var batches = new List<CryptoGrantBatch>();
+        if (space.Mode == ChannelMode.Enc)
+        {
+            var crypto = tx.GetWorkspaceCrypto(id);
+            foreach (var domain in new[] { CryptoDomain.Chat, CryptoDomain.Files })
+            {
+                var currentEpoch = domain == CryptoDomain.Chat ? channel.ChatEpoch : channel.FilesEpoch;
+                if (currentEpoch < 1) throw new WebDropException(ErrorCode.Conflict);
+                var history = domain == CryptoDomain.Chat ? channel.ChatHistory : channel.FilesHistory;
+                if (history)
+                {
+                    var epochs = crypto.Envelopes.Where(e => e.ChannelId == channelId && e.Domain == domain && e.Username == space.CreatorAccount)
+                        .Select(e => e.Epoch).Append(currentEpoch).Distinct().Order().ToList();
+                    if (epochs.Count > 256) throw new WebDropException(ErrorCode.TooLarge);
+                    foreach (var epoch in epochs) batches.Add(new CryptoGrantBatch { Domain = domain, Epoch = epoch, Recipients = [username], Rotate = false });
+                }
+                else
+                {
+                    var recipients = ChannelPolicy.Readers(crypto, channelId, domain).Where(a => (a.Username == space.CreatorAccount || tx.GetChannelMember(id, a.Username) is not null || tx.HasInvitation(id, a.Username)))
+                        .Select(a => a.Username).Append(space.CreatorAccount!).Append(username).Distinct().Order(StringComparer.Ordinal).ToList();
+                    if (recipients.Count > 256) throw new WebDropException(ErrorCode.TooLarge);
+                    batches.Add(new CryptoGrantBatch { Domain = domain, Epoch = currentEpoch + 1, Recipients = recipients, Rotate = true });
+                }
+            }
+        }
+        return new InvitationCryptoPlan { ChannelId = channelId, Username = username, Batches = batches };
+    });
+
+    public void InviteUser(Id16 id, Credentials creds, string username, string payload, IReadOnlyList<DomainEnvelope> envelopes)
+    {
+        if (payload is null || payload.Length is < 1 or > 16_384 || envelopes is null) throw new WebDropException(ErrorCode.BadRequest);
+        store.Write(tx =>
+        {
+            var (space, principal) = Authenticate(tx, id, creds, Membership.None); RequireOwner(principal);
+            if (tx.GetChannelMember(id, username) is not null || tx.HasInvitation(id, username)) throw new WebDropException(ErrorCode.Conflict);
+            if (tx.GetChannelMember(id, username)?.Role == "owner") throw new WebDropException(ErrorCode.Forbidden);
+            var workspace = tx.GetWorkspace(id) ?? throw new WebDropException(ErrorCode.NotFound);
+            var channelId = workspace.DefaultChannelId ?? throw new WebDropException(ErrorCode.Conflict);
+            var channel = workspace.Channels.Find(c => c.Id == channelId) ?? throw new WebDropException(ErrorCode.Conflict);
+            var state = tx.GetWorkspaceCrypto(id);
+            var expected = new List<(CryptoDomain Domain, int Epoch, string Username)>();
+            if (space.Mode == ChannelMode.Enc)
+            {
+                foreach (var domain in new[] { CryptoDomain.Chat, CryptoDomain.Files })
+                {
+                    var currentEpoch = domain == CryptoDomain.Chat ? channel.ChatEpoch : channel.FilesEpoch;
+                    if (currentEpoch < 1) throw new WebDropException(ErrorCode.Conflict);
+                    var history = domain == CryptoDomain.Chat ? channel.ChatHistory : channel.FilesHistory;
+                    if (history)
+                    {
+                        var epochs = state.Envelopes.Where(e => e.ChannelId == channelId && e.Domain == domain && e.Username == space.CreatorAccount)
+                            .Select(e => e.Epoch).Append(currentEpoch).Distinct().Order().ToList();
+                        if (epochs.Count > 256) throw new WebDropException(ErrorCode.TooLarge);
+                        expected.AddRange(epochs.Select(epoch => (domain, epoch, username)));
+                    }
+                    else
+                    {
+                        var recipients = ChannelPolicy.Readers(state, channelId, domain).Where(a => (a.Username == space.CreatorAccount || tx.GetChannelMember(id, a.Username) is not null || tx.HasInvitation(id, a.Username)))
+                            .Select(a => a.Username).Append(space.CreatorAccount!).Append(username).Distinct().ToHashSet(StringComparer.Ordinal);
+                        if (recipients.Count > 256) throw new WebDropException(ErrorCode.TooLarge);
+                        expected.AddRange(recipients.Select(recipient => (domain, currentEpoch + 1, recipient)));
+                    }
+                }
+            }
+            var actual = envelopes.Select(e => (e.Domain, e.Epoch, e.Username)).ToList();
+            if (actual.Count != expected.Count || actual.Distinct().Count() != actual.Count || !actual.ToHashSet().SetEquals(expected)) throw new WebDropException(ErrorCode.BadRequest);
+            foreach (var envelope in envelopes)
+            {
+                if (envelope.ChannelId != channelId || envelope.Payload is null || envelope.Payload.Length is < 1 or > 16_384
+                    || !Enum.IsDefined(envelope.Domain) || envelope.Epoch < 1) throw new WebDropException(ErrorCode.BadRequest);
+                var previous = state.Envelopes.Find(e => e.ChannelId == channelId && e.Domain == envelope.Domain && e.Epoch == envelope.Epoch && e.Username == envelope.Username);
+                if (previous is not null && previous.Payload != envelope.Payload) throw new WebDropException(ErrorCode.Conflict);
+                if (previous is null) state.Envelopes.Add(envelope);
+                if (envelope.Domain == CryptoDomain.Chat) channel.ChatEpoch = Math.Max(channel.ChatEpoch, envelope.Epoch);
+                else channel.FilesEpoch = Math.Max(channel.FilesEpoch, envelope.Epoch);
+            }
+            state.Access.RemoveAll(a => a.ChannelId == channelId && a.Username == username);
+            state.Access.Add(new ChannelAccess
+            {
+                ChannelId = channelId, Username = username, ChatRead = true, ChatWrite = true, FilesRead = true, FilesUpload = true,
+                ChatFromRevision = channel.ChatHistory ? 0 : state.Revision + 1,
+                FilesFromRevision = channel.FilesHistory ? 0 : state.Revision + 1,
+            });
+            state.Revision++;
+            workspace.Revision++;
+            tx.PutWorkspace(id, workspace); tx.PutWorkspaceCrypto(id, state);
+            tx.PutInvitation(new ChannelInvitation(id, username, payload, clock.NowMs));
+            tx.PutKeyPackage(id, username, payload, clock.NowMs); tx.AllowAccount(id, username);
+            return 0;
+        });
+        events.SettingsChanged(id);
+    }
+
+    private static bool CanReadObject(IResourceTx tx, Channel space, Principal principal, Id16 itemId)
+    {
+        var crypto = tx.GetWorkspaceCrypto(space.Id);
+        if (crypto.Access.Count == 0 && crypto.Envelopes.Count == 0 && space.Mode == ChannelMode.Raw) return true;
+        if (crypto.Envelopes.Count == 0 && crypto.Objects.Count == 0 && space.Mode == ChannelMode.Enc) return true;
+        var item = crypto.Objects.Find(o => o.ItemId == itemId.ToBase64Url());
+        if (item is null) return false;
+        if (ChannelPolicy.IsSpaceOwner(space, principal)) return true;
+        if (!ChannelPolicy.CanReadObject(ChannelPolicy.AccessOf(crypto, principal.AccountName, item.ChannelId), item.Domain, item.CreatedRevision)) return false;
+        if (space.Mode == ChannelMode.Raw) return true;
+        return crypto.Envelopes.Exists(e => e.ChannelId == item.ChannelId && e.Domain == item.Domain && e.Epoch == item.Epoch && e.Username == principal.AccountName);
+    }
+
+    private static void CheckObjectWrite(IResourceTx tx, Channel space, Principal principal, Id16 itemId)
+    {
+        var crypto = tx.GetWorkspaceCrypto(space.Id);
+        if (!ChannelPolicy.GrantsEnforced(space, crypto)) return;
+        var item = crypto.Objects.Find(o => o.ItemId == itemId.ToBase64Url()) ?? throw new WebDropException(ErrorCode.BadRequest);
+        if (item.AuthorAccount != principal.AccountName) throw new WebDropException(ErrorCode.Forbidden);
+        var channel = tx.GetWorkspace(space.Id)?.Channels.Find(c => c.Id == item.ChannelId);
+        if (space.Mode == ChannelMode.Enc && channel is not null && item.Epoch != (item.Domain == CryptoDomain.Chat ? channel.ChatEpoch : channel.FilesEpoch)) throw new WebDropException(ErrorCode.Conflict);
+        if (!ChannelPolicy.IsOwner(principal))
+        {
+            var access = ChannelPolicy.AccessOf(crypto, principal.AccountName, item.ChannelId);
+            if (access is null ? space.Mode == ChannelMode.Enc || crypto.Access.Count > 0 : !ChannelPolicy.CanWriteDomain(access, item.Domain)) throw new WebDropException(ErrorCode.Forbidden);
+        }
+    }
+    public CryptoState ReadCrypto(Id16 id, Credentials creds) => store.Read(tx =>
+    {
+        var (space, principal) = Authenticate(tx, id, creds, Membership.Required);
+        var state = tx.GetWorkspaceCrypto(id);
+        if (ChannelPolicy.IsSpaceOwner(space, principal)) return state;
+        var access = state.Access.Where(a => a.Username == principal.AccountName).ToList();
+        var allowed = access.ToDictionary(a => a.ChannelId);
+        bool CanRead(string channelId, CryptoDomain domain) => ChannelPolicy.CanReadDomain(allowed.GetValueOrDefault(channelId), domain);
+        var envelopes = state.Envelopes.Where(e => e.Username == principal.AccountName && CanRead(e.ChannelId, e.Domain)).ToList();
+        var epochs = envelopes.Select(e => (e.ChannelId, e.Domain, e.Epoch)).ToHashSet();
+        return new CryptoState { Envelopes = envelopes,
+            Objects = state.Objects.Where(o => CanRead(o.ChannelId, o.Domain)
+                && (space.Mode == ChannelMode.Raw || epochs.Contains((o.ChannelId, o.Domain, o.Epoch)))).ToList(),
+            Access = access };
+    });
+    public void PublishDomain(Id16 id, Credentials creds, DomainPublishRequest req)
+    {
+        store.Write(tx =>
+        {
+            var (_, principal) = Authenticate(tx, id, creds, Membership.Required); RequireOwner(principal);
+            var workspace = tx.GetWorkspace(id) ?? throw new WebDropException(ErrorCode.NotFound);
+            var channel = workspace.Channels.Find(c => c.Id == req.ChannelId) ?? throw new WebDropException(ErrorCode.NotFound);
+            if (!Enum.IsDefined(req.Domain) || req.Envelopes is null || req.Envelopes.Count != 1 || req.Epoch != 1) throw new WebDropException(ErrorCode.BadRequest);
+            var epoch = req.Domain == CryptoDomain.Chat ? channel.ChatEpoch : channel.FilesEpoch;
+            if (epoch > 1) throw new WebDropException(ErrorCode.Conflict);
+            if (req.Envelopes[0].Username != principal.AccountName || req.Envelopes[0].ChannelId != req.ChannelId || req.Envelopes[0].Domain != req.Domain || req.Envelopes[0].Epoch != 1
+                || req.Envelopes[0].Payload is null || req.Envelopes[0].Payload.Length is < 1 or > 16_384) throw new WebDropException(ErrorCode.BadRequest);
+            var state = tx.GetWorkspaceCrypto(id);
+            var envelope = req.Envelopes[0];
+            var previous = state.Envelopes.Find(e => e.ChannelId == envelope.ChannelId && e.Domain == envelope.Domain && e.Epoch == 1 && e.Username == envelope.Username);
+            if (previous is not null && previous.Payload != envelope.Payload) throw new WebDropException(ErrorCode.Conflict);
+            if (previous is null) state.Envelopes.Add(envelope);
+            var ownerAccess = state.Access.Find(a => a.ChannelId == req.ChannelId && a.Username == principal.AccountName);
+            if (ownerAccess is null) state.Access.Add(new ChannelAccess { ChannelId = req.ChannelId, Username = principal.AccountName!, ChatRead = true, ChatWrite = true, FilesRead = true, FilesUpload = true });
+            if (req.Domain == CryptoDomain.Chat) channel.ChatEpoch = Math.Max(channel.ChatEpoch, req.Epoch); else channel.FilesEpoch = Math.Max(channel.FilesEpoch, req.Epoch);
+            state.Revision++;
+            workspace.Revision++; tx.PutWorkspace(id, workspace); tx.PutWorkspaceCrypto(id, state); return 0;
+        });
+        events.SettingsChanged(id);
+    }
+    public ObjectEnvelope DeclareObject(Id16 id, Credentials creds, ObjectEnvelope req) => store.Write(tx =>
+    {
+        var (space, principal) = Authenticate(tx, id, creds, Membership.Required);
+        if (!ChannelPolicy.CanWrite(space, principal)) throw new WebDropException(ErrorCode.Forbidden);
+        if (!Id16.TryParse(req.ItemId, out _) || !Enum.IsDefined(req.Domain) || req.KeyEnvelope is null || req.KeyEnvelope.Length > 1024) throw new WebDropException(ErrorCode.BadRequest);
+        var workspace = tx.GetWorkspace(id) ?? throw new WebDropException(ErrorCode.NotFound);
+        var channel = workspace.Channels.Find(c => c.Id == req.ChannelId) ?? throw new WebDropException(ErrorCode.NotFound);
+        var state = tx.GetWorkspaceCrypto(id);
+        if (!ChannelPolicy.IsOwner(principal) && (space.Mode == ChannelMode.Enc || state.Access.Count > 0))
+        {
+            if (!ChannelPolicy.CanWriteDomain(ChannelPolicy.AccessOf(state, principal.AccountName, req.ChannelId), req.Domain)) throw new WebDropException(ErrorCode.Forbidden);
+        }
+        if (space.Mode == ChannelMode.Enc && req.Epoch != (req.Domain == CryptoDomain.Chat ? channel.ChatEpoch : channel.FilesEpoch)) throw new WebDropException(ErrorCode.Conflict);
+        var existing = state.Objects.Find(o => o.ItemId == req.ItemId);
+        if (existing is not null)
+        {
+            if (existing.AuthorAccount != principal.AccountName || existing.ChannelId != req.ChannelId || existing.Domain != req.Domain || existing.Epoch != req.Epoch || existing.KeyEnvelope != req.KeyEnvelope) throw new WebDropException(ErrorCode.Conflict);
+            return existing;
+        }
+        if (state.Objects.Count >= 20_000) throw new WebDropException(ErrorCode.TooLarge);
+        req.AuthorAccount = principal.AccountName; req.CreatedRevision = state.Revision + 1; state.Revision++; state.Objects.Add(req); tx.PutWorkspaceCrypto(id, state); return req;
+    });
+    public void SetChannelHistory(Id16 id, Credentials creds, string channelId, bool chat, bool files)
+    {
+        store.Write(tx =>
+        {
+            var (_, principal) = Authenticate(tx, id, creds, Membership.Required); RequireOwner(principal);
+            var workspace = tx.GetWorkspace(id) ?? throw new WebDropException(ErrorCode.NotFound);
+            var channel = workspace.Channels.Find(c => c.Id == channelId) ?? throw new WebDropException(ErrorCode.NotFound);
+            channel.ChatHistory = chat; channel.FilesHistory = files; workspace.Revision++; tx.PutWorkspace(id, workspace); return 0;
+        });
+        events.SettingsChanged(id);
+    }
+}

server/src/WebDrop.Core/Spaces/ChannelWorkspace.cs

@@ -0,0 +1,256 @@
+namespace WebDrop.Core;
+
+public sealed partial class ChannelService
+{
+    public void AccountProfileChanged(string username)
+    {
+        foreach (var id in store.Read(tx => tx.ListAccountSpaces(username, clock.NowMs))) events.SettingsChanged(id);
+    }
+    /// <summary>两个账号是否在同一个空间里(自己总是可以)。成员资料只对有交集的账号开放</summary>
+    public bool SharesSpace(string username, string other) => username == other
+        || store.Read(tx => tx.ListAccountSpaces(username, clock.NowMs).Any(id => tx.GetChannelMember(id, other) is not null));
+    public IReadOnlyList<Id16> AccountSpaceIds(string username) => store.Read(tx => tx.ListAccountSpaces(username, clock.NowMs));
+    public IReadOnlyList<ChannelInfo> AccountSpaces(string username) => store.Read(tx => tx.ListAccountSpaces(username, clock.NowMs).Select(id =>
+    {
+        var channel = tx.GetChannel(id)!;
+        var role = tx.GetChannelMember(id, username)?.Role == "owner" ? Role.Owner : channel.WriteHash is not null ? Role.Write : Role.Read;
+        return ToInfo(channel, tx.CountMembers(id), new Principal(role, username), tx.GetChannelAvatarVersion(id), tx.GetWorkspace(id));
+    }).ToList());
+    private static WorkspaceState NewWorkspace(string username, long now)
+    {
+        var id = Guid.NewGuid().ToString();
+        var state = new WorkspaceState { Revision = 1, DefaultChannelId = id, Channels = [new WorkspaceChannel { Id = id, Name = "常规", CreatedAt = now, CreatedBy = username }] };
+        EnsureDefaultRole(state, now);
+        return state;
+    }
+    /// <summary>补上默认身份组(只补一次)。读取时只在内存里补,下一次写入才落库</summary>
+    private static void EnsureDefaultRole(WorkspaceState state, long now)
+    {
+        if (!state.RolesSeeded)
+        {
+            if (!state.Roles.Any(r => r.Id == WorkspaceRole.DefaultId)) state.Roles.Insert(0, WorkspaceRole.CreateDefault(now));
+            state.RolesSeeded = true;
+        }
+        // Owner 组永远排在最前面
+        if (!state.Roles.Any(r => r.Id == WorkspaceRole.OwnerId)) state.Roles.Insert(0, WorkspaceRole.CreateOwner(now));
+    }
+    public WorkspaceState GetWorkspace(Id16 id, Credentials creds) => store.Read(tx =>
+    {
+        var (space, principal) = Authenticate(tx, id, creds, Membership.Required);
+        var state = tx.GetWorkspace(id) ?? new WorkspaceState();
+        EnsureDefaultRole(state, clock.NowMs);
+        return ViewFor(tx, space, principal, state);
+    });
+    /// <summary>
+    /// 空间结构按调用者的授权裁剪:没授权的频道、目录和条目位置一律不下发。
+    /// 读取和所有修改接口的返回值都必须经过它,否则任何一个成员的一次修改(比如发消息后登记条目位置)
+    /// 都会把整份结构返回给他。
+    /// </summary>
+    private WorkspaceState ViewFor(IResourceTx tx, Channel space, Principal principal, WorkspaceState state)
+    {
+        if (principal.AccountName != space.CreatorAccount)
+        {
+            var crypto = tx.GetWorkspaceCrypto(space.Id);
+            var grants = crypto.Access.Where(a => a.Username == principal.AccountName).ToList();
+            var ids = grants.Where(ChannelPolicy.CanSeeChannel).Select(a => a.ChannelId).ToHashSet();
+            state.Channels.RemoveAll(c => !ids.Contains(c.Id));
+            state.Folders.RemoveAll(f => !ids.Contains(f.ThreadId));
+            state.Locations.RemoveAll(l => !Id16.TryParse(l.ItemId, out var itemId) || !CanReadObject(tx, space, principal, itemId));
+        }
+        state.Locations = state.Locations.Where(l => Id16.TryParse(l.ItemId, out var itemId) && tx.GetItem(space.Id, itemId) is { } item && item.ExpiresAt > clock.NowMs).ToList();
+        return state;
+    }
+    private WorkspaceState ChangeWorkspace(Id16 id, Credentials creds, Action<IResourceTx, WorkspaceState, Principal> change, bool requireAccount = true, string? permission = null)
+    {
+        var state = store.Write(tx =>
+        {
+            var (channel, principal) = Authenticate(tx, id, creds, Membership.Required);
+            var current = tx.GetWorkspace(id) ?? new WorkspaceState();
+            EnsureDefaultRole(current, clock.NowMs);
+            // 被授予对应权限的身份组成员可以代行,不要求频道开放成员上传
+            bool delegated = permission is not null && !ChannelPolicy.IsOwner(principal) && ChannelPolicy.HasPermission(current, principal, permission);
+            if (requireAccount && !ChannelPolicy.IsOwner(principal) && !delegated) throw new WebDropException(ErrorCode.Forbidden);
+            if (!delegated && !ChannelPolicy.CanWrite(channel, principal)) throw new WebDropException(ErrorCode.Forbidden);
+            current.Locations = current.Locations.Where(l => Id16.TryParse(l.ItemId, out var itemId) && tx.GetItem(id, itemId) is not null).ToList();
+            change(tx, current, principal);
+            ValidateWorkspace(current);
+            current.Revision++;
+            tx.PutWorkspace(id, current);
+            // 先落库完整的结构,再按调用者裁剪后返回
+            return ViewFor(tx, channel, principal, current);
+        });
+        events.SettingsChanged(id);
+        return state;
+    }
+    /// <summary>文件域的引用只是个不透明的字符串(文件服务给的域 id),主后端不解释它,只存下来、原样给成员</summary>
+    private static string? FileDomainRef(string? value)
+    {
+        if (string.IsNullOrEmpty(value)) return null;
+        if (value.Length > 64 || !value.All(c => char.IsAsciiLetterOrDigit(c) || c is '-' or '_')) throw new WebDropException(ErrorCode.BadRequest);
+        return value;
+    }
+    public (WorkspaceState State, WorkspaceChannel Channel) CreateWorkspaceChannelResult(Id16 id, Credentials creds, string name, string? groupId, string? fileDomain = null)
+    {
+        string? domain = FileDomainRef(fileDomain);
+        WorkspaceChannel? created = null;
+        var state = ChangeWorkspace(id, creds, (_, workspace, principal) =>
+        {
+            created = new WorkspaceChannel { Id = Guid.NewGuid().ToString(), Name = WorkspaceName(name), GroupId = groupId, CreatedAt = clock.NowMs, CreatedBy = principal.AccountName!, FileDomain = domain };
+            workspace.Channels.Add(created);
+        });
+        return (state, created!);
+    }
+    public WorkspaceState CreateWorkspaceChannel(Id16 id, Credentials creds, string name, string? groupId) => CreateWorkspaceChannelResult(id, creds, name, groupId).State;
+    /// <summary>给还没有文件域的频道指定一个(创建频道时没带,或旧频道)。指定后不能改:文件已经存在那里了</summary>
+    public WorkspaceState SetWorkspaceChannelFileDomain(Id16 id, Credentials creds, string channelId, string fileDomain) => ChangeWorkspace(id, creds, (_, state, _) =>
+    {
+        var channel = FindChannel(state, channelId);
+        string domain = FileDomainRef(fileDomain) ?? throw new WebDropException(ErrorCode.BadRequest);
+        if (channel.FileDomain is not null && channel.FileDomain != domain) throw new WebDropException(ErrorCode.Conflict);
+        channel.FileDomain = domain;
+    }, permission: WorkspacePermission.ManageStructure);
+    public WorkspaceState RenameWorkspaceChannel(Id16 id, Credentials creds, string channelId, string name) => ChangeWorkspace(id, creds, (_, state, _) =>
+        FindChannel(state, channelId).Name = WorkspaceName(name), permission: WorkspacePermission.ManageStructure);
+    public WorkspaceState GroupWorkspaceChannel(Id16 id, Credentials creds, string channelId, string? groupId) => ChangeWorkspace(id, creds, (_, state, _) =>
+        FindChannel(state, channelId).GroupId = groupId, permission: WorkspacePermission.ManageStructure);
+    public (WorkspaceState State, WorkspaceGroup Group) CreateWorkspaceGroupResult(Id16 id, Credentials creds, string name)
+    {
+        WorkspaceGroup? created = null;
+        var state = ChangeWorkspace(id, creds, (_, workspace, _) =>
+        {
+            created = new WorkspaceGroup { Id = Guid.NewGuid().ToString(), Name = WorkspaceName(name), CreatedAt = clock.NowMs };
+            workspace.Groups.Add(created);
+        }, permission: WorkspacePermission.ManageStructure);
+        return (state, created!);
+    }
+    public WorkspaceState CreateWorkspaceGroup(Id16 id, Credentials creds, string name) => CreateWorkspaceGroupResult(id, creds, name).State;
+    public WorkspaceState RenameWorkspaceGroup(Id16 id, Credentials creds, string groupId, string name) => ChangeWorkspace(id, creds, (_, state, _) =>
+        (state.Groups.Find(g => g.Id == groupId) ?? throw new WebDropException(ErrorCode.NotFound)).Name = WorkspaceName(name), permission: WorkspacePermission.ManageStructure);
+    /// <summary>删除分组:组里的频道回到未分组,频道本身和内容都不动</summary>
+    public WorkspaceState DeleteWorkspaceGroup(Id16 id, Credentials creds, string groupId) => ChangeWorkspace(id, creds, (_, state, _) =>
+    {
+        var group = state.Groups.Find(g => g.Id == groupId) ?? throw new WebDropException(ErrorCode.NotFound);
+        foreach (var channel in state.Channels.Where(c => c.GroupId == groupId)) channel.GroupId = null;
+        state.Groups.Remove(group);
+    }, permission: WorkspacePermission.ManageStructure);
+    // ───── 身份组(只有空间主能增删改、分配成员) ─────
+    private static string? RoleLabel(string? value)
+    {
+        value = value?.Trim();
+        if (string.IsNullOrEmpty(value)) return null;
+        if (value.Length > WorkspacePermission.MaxLabelLength || value.Any(char.IsControl)) throw new WebDropException(ErrorCode.BadRequest);
+        return value;
+    }
+    private static void ApplyRole(WorkspaceRole role, string name, string? prefix, string? suffix, string? color, IReadOnlyList<string> permissions)
+    {
+        if (color is not null && !WorkspacePermission.IsValidColor(color)) throw new WebDropException(ErrorCode.BadRequest);
+        if (permissions.Any(p => !WorkspacePermission.All.Contains(p))) throw new WebDropException(ErrorCode.BadRequest);
+        role.Name = WorkspaceName(name); role.Prefix = RoleLabel(prefix); role.Suffix = RoleLabel(suffix); role.Color = color;
+        role.Permissions = permissions.Distinct().ToList();
+    }
+    public (WorkspaceState State, WorkspaceRole Role) CreateWorkspaceRoleResult(Id16 id, Credentials creds, string name, string? prefix, string? suffix, string? color, IReadOnlyList<string> permissions)
+    {
+        WorkspaceRole? created = null;
+        var state = ChangeWorkspace(id, creds, (_, workspace, _) =>
+        {
+            created = new WorkspaceRole { Id = Guid.NewGuid().ToString(), Name = "x", CreatedAt = clock.NowMs };
+            ApplyRole(created, name, prefix, suffix, color, permissions);
+            workspace.Roles.Add(created);
+        });
+        return (state, created!);
+    }
+    public WorkspaceState UpdateWorkspaceRole(Id16 id, Credentials creds, string roleId, string name, string? prefix, string? suffix, string? color, IReadOnlyList<string> permissions) =>
+        ChangeWorkspace(id, creds, (_, state, _) =>
+        {
+            var role = FindRole(state, roleId);
+            // Owner 组的名称和权限固定,只有前后缀和颜色可改
+            if (role.Id == WorkspaceRole.OwnerId) ApplyRole(role, role.Name, prefix, suffix, color, WorkspacePermission.All);
+            else ApplyRole(role, name, prefix, suffix, color, permissions);
+        });
+    public WorkspaceState DeleteWorkspaceRole(Id16 id, Credentials creds, string roleId) =>
+        ChangeWorkspace(id, creds, (_, state, _) =>
+        {
+            var role = FindRole(state, roleId);
+            if (role.Id == WorkspaceRole.OwnerId) throw new WebDropException(ErrorCode.BadRequest);
+            state.Roles.Remove(role);
+        });
+    public WorkspaceState SetWorkspaceRoleMembers(Id16 id, Credentials creds, string roleId, IReadOnlyList<string> members) =>
+        ChangeWorkspace(id, creds, (tx, state, _) =>
+        {
+            var role = FindRole(state, roleId);
+            if (role.Id == WorkspaceRole.OwnerId) throw new WebDropException(ErrorCode.BadRequest);
+            var distinct = members.Select(m => m.Trim().ToLowerInvariant()).Distinct().ToList();
+            if (distinct.Count > 256) throw new WebDropException(ErrorCode.BadRequest);
+            // 只能把已加入空间的账号放进身份组;空间主本来就有全部权限,不必加入
+            foreach (var member in distinct)
+                if (tx.GetChannelMember(id, member) is not { } row || row.Role == "owner") throw new WebDropException(ErrorCode.BadRequest);
+            role.Members = distinct;
+        });
+    private static WorkspaceRole FindRole(WorkspaceState state, string id) => state.Roles.Find(r => r.Id == id) ?? throw new WebDropException(ErrorCode.NotFound);
+    public WorkspaceState CreateWorkspaceFolder(Id16 id, Credentials creds, string threadId, string? parentId, string name) => ChangeWorkspace(id, creds, (_, state, _) =>
+    {
+        FindChannel(state, threadId);
+        state.Folders.Add(new WorkspaceFolder { Id = Guid.NewGuid().ToString(), ThreadId = threadId, ParentId = parentId, Name = WorkspaceName(name) });
+    });
+    public WorkspaceState RenameWorkspaceFolder(Id16 id, Credentials creds, string folderId, string name) => ChangeWorkspace(id, creds, (_, state, _) =>
+        (state.Folders.Find(f => f.Id == folderId) ?? throw new WebDropException(ErrorCode.NotFound)).Name = WorkspaceName(name));
+    public WorkspaceState MoveWorkspaceItems(Id16 id, Credentials creds, string[] itemIds, string threadId, string? folderId) => ChangeWorkspace(id, creds, (tx, state, principal) =>
+    {
+        if (itemIds.Length is < 1 or > 100 || itemIds.Distinct().Count() != itemIds.Length) throw new WebDropException(ErrorCode.BadRequest);
+        // 目的频道必须存在,而且成员只能往自己有写入授权的频道放条目
+        if (!state.Channels.Exists(c => c.Id == threadId)) throw new WebDropException(ErrorCode.NotFound);
+        var space = tx.GetChannel(id)!; var crypto = tx.GetWorkspaceCrypto(id);
+        // 与 CheckObjectWrite 同一口径:加密空间或已有授权记录时,必须有目的频道的写入授权
+        if (!ChannelPolicy.IsSpaceOwner(space, principal) && ChannelPolicy.GrantsEnforced(space, crypto)
+            && !ChannelPolicy.CanWriteAnyDomain(ChannelPolicy.AccessOf(crypto, principal.AccountName, threadId))) throw new WebDropException(ErrorCode.Forbidden);
+        foreach (var itemId in itemIds)
+        {
+            if (!Id16.TryParse(itemId, out var parsed)) throw new WebDropException(ErrorCode.BadRequest);
+            var item = tx.GetItem(id, parsed) ?? throw new WebDropException(ErrorCode.NotFound);
+            if ((item.Flags & (FrameFlags.Control | FrameFlags.Snapshot)) != 0) throw new WebDropException(ErrorCode.BadRequest);
+            if (!ChannelPolicy.IsOwner(principal) && item.AuthorAccount != principal.AccountName) throw new WebDropException(ErrorCode.Forbidden);
+            state.Locations.RemoveAll(l => l.ItemId == itemId);
+            state.Locations.Add(new WorkspaceLocation { ItemId = itemId, ThreadId = threadId, FolderId = folderId, AuthorAccount = item.AuthorAccount });
+        }
+    }, requireAccount: false);
+    private static WorkspaceChannel FindChannel(WorkspaceState state, string id) => state.Channels.Find(c => c.Id == id) ?? throw new WebDropException(ErrorCode.NotFound);
+    private static string WorkspaceName(string name)
+    {
+        if (string.IsNullOrWhiteSpace(name) || name.Trim().Length > 80 || name.Any(char.IsControl)) throw new WebDropException(ErrorCode.BadRequest);
+        return name.Trim();
+    }
+    private static void ValidateWorkspace(WorkspaceState state)
+    {
+        if (state.Roles is null || state.Roles.Count > 32 || state.Roles.Any(r => r is null || r.Members is null || r.Permissions is null)) throw new WebDropException(ErrorCode.BadRequest);
+        if (state.Channels is null || state.Groups is null || state.Folders is null || state.Locations is null
+            || state.Channels.Count > 256 || state.Groups.Count > 128 || state.Folders.Count > 2048 || state.Locations.Count > 10_000)
+            throw new WebDropException(ErrorCode.BadRequest);
+        if (state.Channels.Any(c => c is null) || state.Groups.Any(g => g is null) || state.Folders.Any(f => f is null) || state.Locations.Any(l => l is null)) throw new WebDropException(ErrorCode.BadRequest);
+        var allIds = state.Channels.Select(c => c.Id).Concat(state.Groups.Select(g => g.Id)).Concat(state.Folders.Select(f => f.Id)).Concat(state.Roles.Select(r => r.Id)).ToArray();
+        if (allIds.Any(id => !Guid.TryParseExact(id, "D", out _)) || allIds.Distinct().Count() != allIds.Length) throw new WebDropException(ErrorCode.BadRequest);
+        foreach (var group in state.Groups) group.Name = WorkspaceName(group.Name);
+        foreach (var channel in state.Channels)
+        {
+            channel.Name = WorkspaceName(channel.Name);
+            if (channel.GroupId is not null && !state.Groups.Any(g => g.Id == channel.GroupId)) throw new WebDropException(ErrorCode.BadRequest);
+        }
+        foreach (var folder in state.Folders)
+        {
+            folder.Name = WorkspaceName(folder.Name);
+            _ = FindChannel(state, folder.ThreadId);
+            var visited = new HashSet<string> { folder.Id };
+            for (var parentId = folder.ParentId; parentId is not null;)
+            {
+                var parent = state.Folders.Find(f => f.Id == parentId && f.ThreadId == folder.ThreadId);
+                if (parent is null || !visited.Add(parent.Id)) throw new WebDropException(ErrorCode.BadRequest);
+                parentId = parent.ParentId;
+            }
+        }
+        if (state.Locations.Select(l => l.ItemId).Distinct().Count() != state.Locations.Count) throw new WebDropException(ErrorCode.BadRequest);
+        foreach (var location in state.Locations)
+        {
+            _ = FindChannel(state, location.ThreadId);
+            if (location.FolderId is not null && !state.Folders.Any(f => f.Id == location.FolderId && f.ThreadId == location.ThreadId)) throw new WebDropException(ErrorCode.BadRequest);
+        }
+    }
+}

server/src/WebDrop.Core/Spaces/SignatureCodec.cs

@@ -0,0 +1,122 @@
+using System.Security.Cryptography;
+using System.Text;
+using System.Buffers.Binary;
+
+namespace WebDrop.Core;
+
+/// <summary>Protocol signature framing. Payload encodings are defined by their signed statement type.</summary>
+public static class SignatureCodec
+{
+    private static ReadOnlySpan<byte> Magic => [0x57, 0x44, 0x53, 0x01]; // WDS\x01
+    private const int MaxKindBytes = 64;
+    private const int MaxPayloadBytes = 1_048_576;
+
+    public static byte[] DeviceCertificatePayload(string username, string deviceId, ReadOnlySpan<byte> x, ReadOnlySpan<byte> y)
+    {
+        if (string.IsNullOrEmpty(username) || username.Length > 32 || username.Any(c => !(char.IsAsciiLetterOrDigit(c) || c is '_' or '-'))
+            || !Guid.TryParseExact(deviceId, "D", out _) || x.Length != 32 || y.Length != 32)
+            throw new ArgumentException("Invalid device certificate fields.");
+        var user = Encoding.ASCII.GetBytes(username.ToLowerInvariant());
+        var device = Encoding.ASCII.GetBytes(deviceId.ToLowerInvariant());
+        var payload = new byte[1 + user.Length + 1 + device.Length + 64];
+        int offset = 0;
+        payload[offset++] = (byte)user.Length; user.CopyTo(payload, offset); offset += user.Length;
+        payload[offset++] = (byte)device.Length; device.CopyTo(payload, offset); offset += device.Length;
+        x.CopyTo(payload.AsSpan(offset)); y.CopyTo(payload.AsSpan(offset + 32));
+        return payload;
+    }
+
+    public static byte[] ContentEventPayload(ReadOnlySpan<byte> spaceId, string channelId, string username, string deviceId,
+        ReadOnlySpan<byte> eventId, string eventKind, CryptoDomain domain, int epoch, ReadOnlySpan<byte> itemId,
+        int frameCount, ReadOnlySpan<byte> manifestHash, ReadOnlySpan<byte> targetItemId)
+    {
+        if (spaceId.Length != 16 || eventId.Length != 16 || itemId.Length != 16 || manifestHash.Length != 32
+            || targetItemId.Length is not (0 or 16) || epoch < 0 || frameCount < 1
+            || !Guid.TryParseExact(channelId, "D", out _) || !Enum.IsDefined(domain)
+            || !IsAsciiIdentity(username, 32) || !Guid.TryParseExact(deviceId, "D", out _)
+            || eventKind.Length is < 1 or > 32 || eventKind.Any(c => c is not (>= 'a' and <= 'z') and not '.' and not '-'))
+            throw new ArgumentException("Invalid signed content event fields.");
+
+        byte[] channel = Encoding.ASCII.GetBytes(channelId.ToLowerInvariant());
+        byte[] user = Encoding.ASCII.GetBytes(username.ToLowerInvariant());
+        byte[] device = Encoding.ASCII.GetBytes(deviceId.ToLowerInvariant());
+        byte[] kind = Encoding.ASCII.GetBytes(eventKind);
+        var payload = new byte[16 + 1 + channel.Length + 1 + user.Length + 1 + device.Length + 16 + 1 + kind.Length + 1 + 4 + 16 + 4 + 32 + 1 + 16];
+        int offset = 0;
+        spaceId.CopyTo(payload.AsSpan(offset)); offset += 16;
+        payload[offset++] = (byte)channel.Length; channel.CopyTo(payload, offset); offset += channel.Length;
+        payload[offset++] = (byte)user.Length; user.CopyTo(payload, offset); offset += user.Length;
+        payload[offset++] = (byte)device.Length; device.CopyTo(payload, offset); offset += device.Length;
+        eventId.CopyTo(payload.AsSpan(offset)); offset += 16;
+        payload[offset++] = (byte)kind.Length; kind.CopyTo(payload, offset); offset += kind.Length;
+        payload[offset++] = (byte)domain;
+        BinaryPrimitives.WriteUInt32BigEndian(payload.AsSpan(offset), (uint)epoch); offset += 4;
+        itemId.CopyTo(payload.AsSpan(offset)); offset += 16;
+        BinaryPrimitives.WriteUInt32BigEndian(payload.AsSpan(offset), (uint)frameCount); offset += 4;
+        manifestHash.CopyTo(payload.AsSpan(offset)); offset += 32;
+        payload[offset++] = targetItemId.IsEmpty ? (byte)0 : (byte)1;
+        if (!targetItemId.IsEmpty) targetItemId.CopyTo(payload.AsSpan(offset));
+        return payload;
+    }
+
+    public static byte[] FrameManifestHash(IReadOnlyList<byte[]> frameDigests)
+    {
+        if (frameDigests.Count is < 1 or > 65_536 || frameDigests.Any(d => d.Length != 32)) throw new ArgumentException("Invalid frame manifest.");
+        var data = new byte[8 + frameDigests.Count * 36];
+        "WD1M"u8.CopyTo(data);
+        BinaryPrimitives.WriteUInt32BigEndian(data.AsSpan(4), (uint)frameDigests.Count);
+        int offset = 8;
+        for (int i = 0; i < frameDigests.Count; i++)
+        {
+            BinaryPrimitives.WriteUInt32BigEndian(data.AsSpan(offset), (uint)i); offset += 4;
+            frameDigests[i].CopyTo(data, offset); offset += 32;
+        }
+        return SHA256.HashData(data);
+    }
+
+    private static bool IsAsciiIdentity(string value, int maxLength) => value.Length is >= 3 && value.Length <= maxLength
+        && value.All(c => char.IsAsciiLetterOrDigit(c) || c is '_' or '-');
+
+    public static byte[] BuildMessage(string kind, ReadOnlySpan<byte> payload)
+    {
+        if (string.IsNullOrEmpty(kind) || kind.Length > MaxKindBytes
+            || kind[0] is < 'a' or > 'z'
+            || kind.Any(c => c is not (>= 'a' and <= 'z') and not (>= '0' and <= '9') and not '.' and not '_' and not '-'))
+            throw new ArgumentException("Invalid signature kind.", nameof(kind));
+        if (payload.Length > MaxPayloadBytes) throw new ArgumentOutOfRangeException(nameof(payload));
+
+        var kindBytes = Encoding.ASCII.GetBytes(kind);
+        var message = new byte[Magic.Length + 2 + kindBytes.Length + 4 + payload.Length];
+        int offset = 0;
+        Magic.CopyTo(message.AsSpan(offset)); offset += Magic.Length;
+        message[offset++] = (byte)(kindBytes.Length >> 8);
+        message[offset++] = (byte)kindBytes.Length;
+        kindBytes.CopyTo(message, offset); offset += kindBytes.Length;
+        uint length = (uint)payload.Length;
+        message[offset++] = (byte)(length >> 24);
+        message[offset++] = (byte)(length >> 16);
+        message[offset++] = (byte)(length >> 8);
+        message[offset++] = (byte)length;
+        payload.CopyTo(message.AsSpan(offset));
+        return message;
+    }
+
+    /// <summary>Verifies WebCrypto ECDSA P-256/SHA-256 signatures in fixed-width IEEE P1363 form.</summary>
+    public static bool VerifyP256(ReadOnlySpan<byte> x, ReadOnlySpan<byte> y, string kind,
+        ReadOnlySpan<byte> payload, ReadOnlySpan<byte> signature)
+    {
+        if (x.Length != 32 || y.Length != 32 || signature.Length != 64) return false;
+        try
+        {
+            using var key = ECDsa.Create(new ECParameters
+            {
+                Curve = ECCurve.NamedCurves.nistP256,
+                Q = new ECPoint { X = x.ToArray(), Y = y.ToArray() },
+            });
+            return key.VerifyData(BuildMessage(kind, payload), signature, HashAlgorithmName.SHA256,
+                DSASignatureFormat.IeeeP1363FixedFieldConcatenation);
+        }
+        catch (ArgumentException) { return false; }
+        catch (CryptographicException) { return false; }
+    }
+}

server/src/WebDrop.Core/Spaces/Workspace.cs

@@ -0,0 +1,101 @@
+using System.Text.Json.Serialization;
+
+namespace WebDrop.Core;
+
+public sealed class WorkspaceChannel
+{
+    [JsonPropertyName("chatEpoch")] public int ChatEpoch { get; set; }
+    [JsonPropertyName("filesEpoch")] public int FilesEpoch { get; set; }
+    [JsonPropertyName("chatHistory")] public bool ChatHistory { get; set; } = true;
+    [JsonPropertyName("filesHistory")] public bool FilesHistory { get; set; } = true;
+    /// <summary>这个频道的文件域在文件服务里的 id。不透明字符串:创建、容量、用量都归文件服务管,这里只是引用。null 表示还没分配</summary>
+    [JsonPropertyName("fileDomain")] public string? FileDomain { get; set; }
+    [JsonPropertyName("id")] public required string Id { get; init; }
+    [JsonPropertyName("name")] public required string Name { get; set; }
+    [JsonPropertyName("createdAt")] public required long CreatedAt { get; init; }
+    [JsonPropertyName("createdBy")] public required string CreatedBy { get; init; }
+    [JsonPropertyName("groupId")] public string? GroupId { get; set; }
+}
+public sealed class WorkspaceGroup
+{
+    [JsonPropertyName("id")] public required string Id { get; init; }
+    [JsonPropertyName("name")] public required string Name { get; set; }
+    [JsonPropertyName("createdAt")] public required long CreatedAt { get; init; }
+}
+public sealed class WorkspaceFolder
+{
+    [JsonPropertyName("id")] public required string Id { get; init; }
+    [JsonPropertyName("threadId")] public required string ThreadId { get; init; }
+    [JsonPropertyName("parentId")] public string? ParentId { get; init; }
+    [JsonPropertyName("name")] public required string Name { get; set; }
+}
+public sealed class WorkspaceLocation
+{
+    [JsonPropertyName("itemId")] public required string ItemId { get; init; }
+    [JsonPropertyName("threadId")] public required string ThreadId { get; init; }
+    [JsonPropertyName("folderId")] public string? FolderId { get; init; }
+    [JsonPropertyName("authorAccount")] public string? AuthorAccount { get; init; }
+}
+/// <summary>身份组可授予的权限。空间主拥有全部权限,不属于任何身份组</summary>
+public static partial class WorkspacePermission
+{
+    /// <summary>移除成员、撤销邀请</summary>
+    public const string RemoveMembers = "members.remove";
+    /// <summary>重命名频道、调整频道所属分组、管理分组(新建频道涉及密钥,仍只有空间主)</summary>
+    public const string ManageStructure = "structure.manage";
+    public static readonly IReadOnlyList<string> All = [RemoveMembers, ManageStructure];
+    /// <summary>前后缀(支持行内 Markdown)的长度上限:界面不限制,这里只防止空间数据被撑大</summary>
+    public const int MaxLabelLength = 2000;
+    /// <summary>预设名,或自定义:纯色 "#rrggbb"、渐变 "g:#rrggbb,#rrggbb[,#rrggbb]"(2~5 个色标,从左到右);后面可以接动画效果 "|breathe"(呼吸) "|blink"(闪烁) "|marquee"(跑马灯,仅渐变) "|cycle"(色相循环)</summary>
+    public static bool IsValidColor(string color) => Colors.Contains(color) || CustomColor().IsMatch(color);
+    [System.Text.RegularExpressions.GeneratedRegex("^(#[0-9a-fA-F]{6}|g:#[0-9a-fA-F]{6}(,#[0-9a-fA-F]{6}){1,4})(\\|(breathe|blink|marquee|cycle))?$")]
+    private static partial System.Text.RegularExpressions.Regex CustomColor();
+    /// <summary>早期版本的预设色名,老数据里可能还有;新的界面只写自定义颜色</summary>
+    public static readonly IReadOnlyList<string> Colors = ["gray", "blue", "green", "amber", "red", "purple", "sunset", "ocean", "aurora", "candy", "gold", "rainbow"];
+}
+public sealed class WorkspaceRole
+{
+    /// <summary>空间主所在的「Owner 组」,每个空间都有,id 固定。成员就是空间主本人,权限固定为全部,只能改前后缀和颜色</summary>
+    public const string OwnerId = "00000000-0000-4000-8000-000000000000";
+    public static WorkspaceRole CreateOwner(long now) => new()
+    {
+        Id = OwnerId, Name = "Owner 组", Suffix = "Owner", Color = "g:#d99a1c,#f2c94c,#c27a0a", CreatedAt = now,
+        Permissions = [.. WorkspacePermission.All],
+    };
+
+    /// <summary>每个空间都有的默认「管理组」,id 固定,老空间第一次读写时补上</summary>
+    public const string DefaultId = "00000000-0000-4000-8000-000000000001";
+    public static WorkspaceRole CreateDefault(long now) => new()
+    {
+        Id = DefaultId, Name = "管理组", Suffix = "管理员", Color = "#3b6ea8", CreatedAt = now,
+        Permissions = [.. WorkspacePermission.All],
+    };
+
+    [JsonPropertyName("id")] public required string Id { get; init; }
+    [JsonPropertyName("name")] public required string Name { get; set; }
+    /// <summary>聊天里显示在名字前、后的文字(如「频道主」「管理员」),可只填其一</summary>
+    [JsonPropertyName("prefix")] public string? Prefix { get; set; }
+    [JsonPropertyName("suffix")] public string? Suffix { get; set; }
+    [JsonPropertyName("color")] public string? Color { get; set; }
+    [JsonPropertyName("permissions")] public List<string> Permissions { get; set; } = [];
+    [JsonPropertyName("members")] public List<string> Members { get; set; } = [];
+    [JsonPropertyName("createdAt")] public required long CreatedAt { get; init; }
+}
+public sealed class WorkspaceState
+{
+    [JsonPropertyName("defaultChannelId")] public string? DefaultChannelId { get; init; }
+    [JsonPropertyName("revision")] public long Revision { get; set; }
+    [JsonPropertyName("channels")] public List<WorkspaceChannel> Channels { get; init; } = [];
+    [JsonPropertyName("groups")] public List<WorkspaceGroup> Groups { get; init; } = [];
+    /// <summary>旧版本存下来的结构里没有 roles,反序列化后是 null,这里统一当作空列表</summary>
+    [JsonPropertyName("roles")] public List<WorkspaceRole> Roles { get => _roles ??= []; init => _roles = value; }
+    private List<WorkspaceRole>? _roles;
+    /// <summary>默认身份组已经放进来过。之后空间主删掉它不会再自动出现</summary>
+    [JsonPropertyName("rolesSeeded")] public bool RolesSeeded { get; set; }
+    [JsonPropertyName("folders")] public List<WorkspaceFolder> Folders { get; init; } = [];
+    [JsonPropertyName("locations")] public List<WorkspaceLocation> Locations { get; set; } = [];
+}
+
+[JsonSerializable(typeof(WorkspaceState))]
+[JsonSourceGenerationOptions(DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull)]
+public sealed partial class WorkspaceJson : JsonSerializerContext;

server/src/WebDrop.Core/Spaces/WorkspaceCrypto.cs

@@ -0,0 +1,85 @@
+using System.Text.Json.Serialization;
+
+namespace WebDrop.Core;
+
+public sealed class DomainEnvelope
+{
+    [JsonPropertyName("channelId")] public required string ChannelId { get; init; }
+    [JsonPropertyName("domain")] public required CryptoDomain Domain { get; init; }
+    [JsonPropertyName("epoch")] public required int Epoch { get; init; }
+    [JsonPropertyName("username")] public required string Username { get; init; }
+    [JsonPropertyName("payload")] public required string Payload { get; init; }
+}
+public sealed class ObjectEnvelope
+{
+    [JsonPropertyName("createdRevision")] public long CreatedRevision { get; set; }
+    [JsonPropertyName("itemId")] public required string ItemId { get; init; }
+    [JsonPropertyName("channelId")] public required string ChannelId { get; init; }
+    [JsonPropertyName("domain")] public required CryptoDomain Domain { get; init; }
+    [JsonPropertyName("epoch")] public required int Epoch { get; init; }
+    [JsonPropertyName("keyEnvelope")] public required string KeyEnvelope { get; init; }
+    [JsonPropertyName("authorAccount")] public string? AuthorAccount { get; set; }
+    [JsonPropertyName("event")] public SignedContentEventRecord? Event { get; set; }
+    [JsonPropertyName("deleteEvent")] public SignedContentEventRecord? DeleteEvent { get; set; }
+}
+
+public sealed class SignedContentEventRecord
+{
+    [JsonPropertyName("eventId")] public required string EventId { get; init; }
+    [JsonPropertyName("kind")] public required string Kind { get; init; }
+    [JsonPropertyName("frameCount")] public required int FrameCount { get; init; }
+    [JsonPropertyName("manifestHash")] public required string ManifestHash { get; init; }
+    [JsonPropertyName("signerDeviceId")] public required string SignerDeviceId { get; init; }
+    /// <summary>签名者的账号。空间主撤回别人的消息时,签名者不是作者;旧记录没有这个字段,按作者处理</summary>
+    [JsonPropertyName("signerAccount")] public string? SignerAccount { get; init; }
+    [JsonPropertyName("signature")] public required string Signature { get; init; }
+    [JsonPropertyName("targetItemId")] public string? TargetItemId { get; init; }
+    [JsonPropertyName("signerRootPublicKey")] public required string SignerRootPublicKey { get; init; }
+    [JsonPropertyName("signerDevicePublicKey")] public required string SignerDevicePublicKey { get; init; }
+    [JsonPropertyName("deviceCertificateSignature")] public required string DeviceCertificateSignature { get; init; }
+}
+
+public sealed record SignedContentEventProof(byte[] EventIdBytes, string EventKind, string Username, string ChannelId, CryptoDomain Domain, int Epoch,
+    int FrameCount, byte[] ManifestHash, string DeviceId, byte[] Signature, string? TargetItemId,
+    string RootPublicKey, string DevicePublicKey, byte[] DeviceCertificateSignature);
+public sealed class ChannelAccess
+{
+    [JsonPropertyName("chatFromRevision")] public long ChatFromRevision { get; set; }
+    [JsonPropertyName("channelId")] public required string ChannelId { get; init; }
+    [JsonPropertyName("filesFromRevision")] public long FilesFromRevision { get; set; }
+    [JsonPropertyName("username")] public required string Username { get; init; }
+    [JsonPropertyName("chatRead")] public bool ChatRead { get; set; } = true;
+    [JsonPropertyName("chatWrite")] public bool ChatWrite { get; set; } = true;
+    [JsonPropertyName("filesRead")] public bool FilesRead { get; set; } = true;
+    [JsonPropertyName("filesUpload")] public bool FilesUpload { get; set; } = true;
+}
+public sealed class CryptoGrantBatch
+{
+    [JsonPropertyName("domain")] public required CryptoDomain Domain { get; init; }
+    [JsonPropertyName("epoch")] public required int Epoch { get; init; }
+    [JsonPropertyName("recipients")] public required List<string> Recipients { get; init; }
+    [JsonPropertyName("rotate")] public required bool Rotate { get; init; }
+}
+public sealed class InvitationCryptoPlan
+{
+    [JsonPropertyName("channelId")] public required string ChannelId { get; init; }
+    [JsonPropertyName("username")] public required string Username { get; init; }
+    [JsonPropertyName("batches")] public required List<CryptoGrantBatch> Batches { get; init; }
+}
+public sealed class CryptoState
+{
+    [JsonPropertyName("revision")] public long Revision { get; set; }
+    [JsonPropertyName("envelopes")] public List<DomainEnvelope> Envelopes { get; init; } = [];
+    [JsonPropertyName("objects")] public List<ObjectEnvelope> Objects { get; init; } = [];
+    [JsonPropertyName("access")] public List<ChannelAccess> Access { get; init; } = [];
+}
+public sealed class DomainPublishRequest
+{
+    [JsonPropertyName("channelId")] public required string ChannelId { get; init; }
+    [JsonPropertyName("domain")] public required CryptoDomain Domain { get; init; }
+    [JsonPropertyName("epoch")] public required int Epoch { get; init; }
+    [JsonPropertyName("envelopes")] public required List<DomainEnvelope> Envelopes { get; init; }
+}
+
+[JsonSerializable(typeof(CryptoState))]
+public sealed partial class WorkspaceCryptoJson : JsonSerializerContext;

server/src/WebDrop.Core/WebDrop.Core.csproj

@@ -6,4 +6,8 @@
     <Nullable>enable</Nullable>
   </PropertyGroup>
 
+  <ItemGroup>
+    <ProjectReference Include="..\WebDrop.FileProtocol\WebDrop.FileProtocol.csproj" />
+  </ItemGroup>
+
 </Project>

server/src/WebDrop.FileApi/DomainStore.cs

@@ -0,0 +1,45 @@
+using System.Security.Cryptography;
+using System.Text.Json;
+using WebDrop.FileProtocol;
+
+namespace WebDrop.FileApi;
+
+/// <summary>
+/// 文件域的登记:一个域一个小 JSON 文件({数据目录}/domains/{id}.json),记录它属于哪个空间、分配了多大。
+/// 域 id 是文件服务随机生成的,和主后端的任何 id 无关;用了多少字节由 <see cref="FrameStore"/> 按顶层目录统计。
+/// </summary>
+public sealed class DomainStore
+{
+    private readonly string _root;
+
+    public DomainStore(string root)
+    {
+        _root = Path.GetFullPath(root);
+        Directory.CreateDirectory(_root);
+    }
+
+    private string PathOf(string id) => Path.Combine(_root, id + ".json");
+
+    public FileDomainBody Create(string space, long quota, long nowMs)
+    {
+        var domain = new FileDomainBody(Convert.ToHexStringLower(RandomNumberGenerator.GetBytes(16)), space, quota, 0, nowMs);
+        string tmp = PathOf(domain.Id) + "." + Guid.NewGuid().ToString("N") + ".tmp";
+        File.WriteAllText(tmp, JsonSerializer.Serialize(domain, FileProtocolJson.Default.FileDomainBody));
+        File.Move(tmp, PathOf(domain.Id), overwrite: false);
+        return domain;
+    }
+
+    public FileDomainBody? Get(string id)
+    {
+        if (!FileWire.IsHex32(id)) return null;
+        try { return JsonSerializer.Deserialize(File.ReadAllText(PathOf(id)), FileProtocolJson.Default.FileDomainBody); }
+        catch (Exception e) when (e is IOException or JsonException) { return null; }
+    }
+
+    public bool Delete(string id)
+    {
+        if (!FileWire.IsHex32(id) || !File.Exists(PathOf(id))) return false;
+        File.Delete(PathOf(id));
+        return true;
+    }
+}

server/src/WebDrop.FileApi/FileApiApp.cs

@@ -0,0 +1,177 @@
+using System.Security.Cryptography;
+using System.Text;
+using WebDrop.FileProtocol;
+
+namespace WebDrop.FileApi;
+
+public static class FileApiApp
+{
+    public static WebApplication Build(string[] args, Action<WebApplicationBuilder>? configure = null)
+    {
+        var builder = WebApplication.CreateSlimBuilder(args);
+        configure?.Invoke(builder);
+        var options = builder.Configuration.GetSection("FileApi").Get<FileApiOptions>() ?? new FileApiOptions();
+        if (options.Secret.Length < 32) throw new InvalidOperationException("FileApi:Secret 至少 32 个字符(和主后端的 WebDrop:Files:Secret 一致)");
+        if (Array.IndexOf(options.EffectiveChoices, options.DefaultQuota) < 0) throw new InvalidOperationException("FileApi:DefaultQuota 必须是 FileApi:QuotaChoices 里的一档");
+
+        builder.WebHost.ConfigureKestrel(k =>
+        {
+            k.AddServerHeader = false;
+            k.Limits.MaxRequestBodySize = options.MaxFrameBytes;
+        });
+        builder.Services.AddSingleton(options);
+        builder.Services.AddSingleton(new FrameStore(Path.Combine(options.DataDir, "frames"), options.MaxStoreBytes, Path.Combine(options.DataDir, "sync")));
+        var domains = new DomainStore(Path.Combine(options.DataDir, "domains"));
+        builder.Services.AddSingleton(domains);
+        builder.Services.AddHostedService<PendingSweeper>();
+        builder.Services.AddSingleton<SyncWorker>();
+        builder.Services.AddHostedService(sp => sp.GetRequiredService<SyncWorker>());
+        if (options.CorsOrigins.Length > 0)
+        {
+            builder.Services.AddCors(c => c.AddDefaultPolicy(p => p
+                .WithOrigins(options.CorsOrigins)
+                .WithMethods("GET", "PUT", "POST", "DELETE", "OPTIONS")
+                .WithHeaders(FileWire.TicketHeader, "Content-Type")
+                .WithExposedHeaders("Retry-After")
+                .SetPreflightMaxAge(TimeSpan.FromHours(1))));
+        }
+
+        var app = builder.Build();
+        app.Use(async (ctx, next) =>
+        {
+            var h = ctx.Response.Headers;
+            h["Referrer-Policy"] = "no-referrer";
+            h["X-Content-Type-Options"] = "nosniff";
+            h["Cache-Control"] = "no-store";
+            h["Content-Security-Policy"] = "default-src 'none'; frame-ancestors 'none'";
+            try { await next(ctx); }
+            catch (OperationCanceledException) when (ctx.RequestAborted.IsCancellationRequested) { }
+            catch (BadHttpRequestException e)
+            {
+                if (!ctx.Response.HasStarted) { ctx.Response.StatusCode = e.StatusCode; await ctx.Response.WriteAsync("{\"error\":\"bad_request\"}"); }
+            }
+        });
+        if (options.CorsOrigins.Length > 0) app.UseCors();
+        Map(app, options, app.Services.GetRequiredService<FrameStore>(), domains);
+        return app;
+    }
+
+    private static void Map(WebApplication app, FileApiOptions options, FrameStore store, DomainStore domains)
+    {
+        byte[] secret = Encoding.UTF8.GetBytes(options.Secret);
+
+        // 校验票据,规则只在这里:文件域、条目必须和路径一致;票据必须是这个域所属的空间签发的;
+        // 读取、删除的票据只能用一次(下载次数在主后端签票据时计,重放同一张票据等于绕过计次);管理票据(运维用)对任何条目有效
+        var usedTickets = new UsedTickets();
+        FileTicket? Authorize(HttpContext ctx, FileOp op, string channel, string? item)
+        {
+            if (!FileTokens.TryVerify(secret, ctx.Request.Headers[FileWire.TicketHeader].ToString(), DateTimeOffset.UtcNow.ToUnixTimeMilliseconds(), out FileTicket ticket)) return null;
+            if (ticket.Op == FileOp.Admin) return ticket;
+            if (!(ticket.Op == op && ticket.Channel == channel && (item is null || ticket.Item == item))) return null;
+            // 票据是哪个空间签的,必须就是域所属的那个空间(别的空间即使拿到域 id 也用不了)
+            if (domains.Get(channel) is not { } domain || domain.Space != ticket.Space) return null;
+            if (op is FileOp.Get or FileOp.Delete && !usedTickets.TryUse(ticket.Jti, ticket.ExpiresMs)) return null;
+            return ticket;
+        }
+        IResult Error(int status, string code) => Results.Text($"{{\"error\":\"{code}\"}}", "application/json", Encoding.UTF8, status);
+
+        app.MapGet("/healthz", () => Results.Text("ok"));
+
+        // 文件域的选项(创建时可选的容量档位):不含任何机密,谁都能读,前端创建文件域前来看
+        app.MapGet("/file/v1/options", () => Results.Text(System.Text.Json.JsonSerializer.Serialize(options.Domain, FileProtocolJson.Default.FileDomainOptions), "application/json"));
+
+        app.MapGet("/file/v1/info", (HttpContext ctx) =>
+            FileTokens.TryVerify(secret, ctx.Request.Headers[FileWire.TicketHeader].ToString(), DateTimeOffset.UtcNow.ToUnixTimeMilliseconds(), out FileTicket t) && t.Op == FileOp.Admin
+                ? Results.Text($"{{\"used_bytes\":{store.UsedBytes},\"free_bytes\":{store.FreeBytes}}}", "application/json")
+                : Error(401, "unauthorized"));
+
+        // 存一帧:请求体是完整的帧封装。域必须存在,写入受域的容量限制。返回这一帧的摘要,客户端拿它去主后端登记
+        app.MapPut("/file/v1/domains/{id}/items/{item}/frames/{index:long}", async (string id, string item, long index, HttpContext ctx, CancellationToken ct) =>
+        {
+            if (!FileWire.IsHex32(id) || !FileWire.IsHex32(item) || index is < 0 or > uint.MaxValue) return Error(400, "bad_request");
+            if (Authorize(ctx, FileOp.Put, id, item) is null) return Error(401, "unauthorized");
+            if (domains.Get(id) is not { } domain) return Error(404, "not_found");
+            if (ctx.Request.ContentLength is not { } length || length < FrameHeader.Size || length > options.MaxFrameBytes) return Error(413, "too_large");
+
+            byte[] frame = new byte[length];
+            await ctx.Request.Body.ReadExactlyAsync(frame, ct).ConfigureAwait(false);
+            if (!FrameHeader.TryParse(frame, out var header) || header.TotalLength != frame.Length || header.ItemHex != item || header.Index != index)
+                return Error(400, "bad_request");
+
+            byte[] digest = SHA256.HashData(frame);
+            switch (await store.PutAsync(id, item, (uint)index, frame, digest, ct, domain.Quota).ConfigureAwait(false))
+            {
+                case PutResult.Conflict: return Error(409, "conflict");
+                case PutResult.Full: return Error(507, "store_full");
+                case PutResult.OverQuota: return Error(507, "quota_exceeded");
+            }
+            return Results.Text($"{{\"digest\":\"{Convert.ToHexStringLower(digest)}\",\"length\":{frame.Length}}}", "application/json", Encoding.UTF8, 200);
+        });
+
+        // 读取:自 from 起把连续的帧原样顺序写出
+        app.MapGet("/file/v1/domains/{id}/items/{item}/frames", async (string id, string item, HttpContext ctx, CancellationToken ct) =>
+        {
+            if (!FileWire.IsHex32(id) || !FileWire.IsHex32(item)) return Error(400, "bad_request");
+            var ticket = Authorize(ctx, FileOp.Get, id, item);
+            if (ticket is null) return Error(401, "unauthorized");
+            if (!uint.TryParse(ctx.Request.Query["from"], out uint from)) from = ticket.From;
+            if (ticket.Op != FileOp.Admin && from < ticket.From) return Error(403, "forbidden");
+
+            ctx.Response.ContentType = "application/octet-stream";
+            bool any = false;
+            foreach (var path in store.FramesFrom(id, item, from))
+            {
+                any = true;
+                await ctx.Response.SendFileAsync(path, ct).ConfigureAwait(false);
+            }
+            return any ? Results.Empty : Error(404, "not_found");
+        });
+
+        // 删一个条目的所有帧:删除票据(主后端确认调用者有权删除之后签发),或者上传这个条目的票据(取消上传时清掉自己传的字节)
+        app.MapDelete("/file/v1/domains/{id}/items/{item}", (string id, string item, HttpContext ctx) =>
+        {
+            if (!FileWire.IsHex32(id) || !FileWire.IsHex32(item)) return Error(400, "bad_request");
+            if (Authorize(ctx, FileOp.Delete, id, item) is null && Authorize(ctx, FileOp.Put, id, item) is null) return Error(401, "unauthorized");
+            return store.DeletePrefix($"{id}/{item}") ? Results.NoContent() : Error(400, "bad_request");
+        });
+
+        // 确认一个条目:整个文件已经登记到主后端。持上传这个条目的票据
+        app.MapPost("/file/v1/domains/{id}/items/{item}/commit", (string id, string item, HttpContext ctx) =>
+        {
+            if (!FileWire.IsHex32(id) || !FileWire.IsHex32(item)) return Error(400, "bad_request");
+            if (Authorize(ctx, FileOp.Put, id, item) is null) return Error(401, "unauthorized");
+            return store.Commit(id, item) ? Results.NoContent() : Error(404, "not_found");
+        });
+
+        // ───── 文件域:创建、查询、删除。前端带着空间签发的票据直接来这里
+        // 创建:票据必须是 Create(空间的所有者/管理员向主后端申请的),Channel 字段是空间 id
+        app.MapPost("/file/v1/domains", async (HttpContext ctx, CancellationToken ct) =>
+        {
+            if (!FileTokens.TryVerify(secret, ctx.Request.Headers[FileWire.TicketHeader].ToString(), DateTimeOffset.UtcNow.ToUnixTimeMilliseconds(), out FileTicket ticket)
+                || ticket.Op is not (FileOp.Create or FileOp.Admin)) return Error(401, "unauthorized");
+            if (!FileWire.IsHex32(ticket.Channel)) return Error(400, "bad_request");
+            var request = ctx.Request.ContentLength is 0 ? new FileDomainCreate() : await ctx.Request.ReadFromJsonAsync(FileProtocolJson.Default.FileDomainCreate, ct).ConfigureAwait(false) ?? new FileDomainCreate();
+            long quota = request.Quota == 0 ? options.DefaultQuota : request.Quota;
+            if (Array.IndexOf(options.EffectiveChoices, quota) < 0) return Error(400, "bad_quota");
+            var created = domains.Create(ticket.Channel, quota, DateTimeOffset.UtcNow.ToUnixTimeMilliseconds());
+            return Results.Text(System.Text.Json.JsonSerializer.Serialize(created, FileProtocolJson.Default.FileDomainBody), "application/json", Encoding.UTF8, 201);
+        });
+        // 查询:持有这个域的读、写或管理票据都可以
+        app.MapGet("/file/v1/domains/{id}", (string id, HttpContext ctx) =>
+        {
+            if (!FileWire.IsHex32(id)) return Error(400, "bad_request");
+            if (Authorize(ctx, FileOp.Get, id, null) is null && Authorize(ctx, FileOp.Put, id, null) is null) return Error(401, "unauthorized");
+            if (domains.Get(id) is not { } domain) return Error(404, "not_found");
+            return Results.Text(System.Text.Json.JsonSerializer.Serialize(domain with { Used = store.UsedBy(id) }, FileProtocolJson.Default.FileDomainBody), "application/json");
+        });
+        // 删除域和里面所有文件:只有管理票据(运维用)
+        app.MapDelete("/file/v1/domains/{id}", (string id, HttpContext ctx) =>
+        {
+            if (!FileWire.IsHex32(id)) return Error(400, "bad_request");
+            if (Authorize(ctx, FileOp.Admin, "*", null) is null) return Error(401, "unauthorized");
+            if (!domains.Delete(id)) return Error(404, "not_found");
+            store.DeletePrefix(id);
+            return Results.NoContent();
+        });
+    }
+}