ci: build and release webdrop-api and webdrop-files as separate images [CI]

- dev images are built only when the push touched code that image uses (path filters);
  webdrop-files does not wait for the frontend build
- one v* tag releases both images (:tag and :latest) after the shared checks
- registry build and push live in scripts/ci-publish-image.sh, used by every workflow
- containers: fix the api Containerfile (missing Sync project), add Containerfile.files,
  Quadlet units for the file service (prod and dev), env examples, and registry
  auto-update for the production units so each machine pulls only the image it runs

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