feat: signed releases and a host-side updater for container nodes

CI signs the image digest of each agent and probe release; the panel only
stores and forwards it. Nodes write the manifest to their data directory and
a host updater verifies the signature with a local public key, pulls by
digest, restarts the unit and rolls back when it is unhealthy. The panel can
list releases, ask a node to update and show the reported update state.

ci/build-main-amd64.sh

@@ -68,7 +68,7 @@ done
 for tag in latest "$dev_tag"; do
   pushed=false
   for attempt in 1 2 3; do
-    if buildah push --tls-verify=true "$local_image" "docker://$repository:$tag"; then
+    if buildah push --tls-verify=true --digestfile "$work/$component.digest" "$local_image" "docker://$repository:$tag"; then
       pushed=true
       break
     fi
@@ -80,3 +80,15 @@ for tag in latest "$dev_tag"; do
   [[ "$pushed" == true ]] || { echo "could not push $repository:$tag after 3 attempts" >&2; exit 1; }
   echo "pushed development image $repository:$tag"
 done
+
+# 发布清单：给镜像的 digest 签名（私钥只在 CI 密钥里），再登记到面板；面板把它原样转给在线的节点，节点宿主机上的更新器用本机的公钥验签后才会更新。
+# 没有配置签名密钥（例如 fork）就只构建镜像、不发清单。
+if [[ -n "${RELEASE_SIGNING_KEY:-}" ]]; then
+  digest="$(cat "$work/$component.digest")"
+  release_dir="$work/$component-release"
+  bash "$root/ci/release-manifest.sh" "$component" "$repository" "$digest" "$dev_tag" dev "$release_dir"
+  if [[ -n "${RELEASE_API_URL:-}" && -n "${RELEASE_API_TOKEN:-}" ]]; then
+    python3 -c 'import json,sys; print(json.dumps({"manifest": open(sys.argv[1]).read(), "signature": open(sys.argv[2]).read()}))'       "$release_dir/manifest.json" "$release_dir/manifest.sig"       | curl --fail-with-body --silent --show-error --retry 3 -X POST "${RELEASE_API_URL%/}/api/admin/releases"           -H "Authorization: Bearer $RELEASE_API_TOKEN" -H 'Content-Type: application/json' --data-binary @- >/dev/null
+    echo "registered the signed $component release with the panel"
+  fi
+fi

ci/release-manifest.sh

@@ -0,0 +1,30 @@
+#!/usr/bin/env bash
+# 生成并签名一个镜像的发布清单：ci/release-manifest.sh <组件> <镜像仓库> <digest> <tag> <通道> <输出目录>
+# 签名私钥从环境变量 RELEASE_SIGNING_KEY（PEM 内容）读取，只写进一个 600 权限的临时文件，用完即删；私钥只放在 CI 密钥里，不进仓库、不上传面板。
+# 输出：<输出目录>/manifest.json（扁平 JSON，签名对象是它的原始字节）和 manifest.sig（base64 的 DER ECDSA 签名）。
+set -euo pipefail
+
+component="${1:?usage: release-manifest.sh <component> <repository> <digest> <tag> <channel> <outdir>}"
+repository="${2:?}"; digest="${3:?}"; tag="${4:?}"; channel="${5:?}"; outdir="${6:?}"
+[[ "$component" =~ ^(agent|probe|backend)$ ]] || { echo "unsupported component: $component" >&2; exit 2; }
+[[ "$digest" =~ ^sha256:[0-9a-f]{64}$ ]] || { echo "digest must look like sha256:<64 hex>" >&2; exit 2; }
+[[ "$repository" =~ ^[a-z0-9./_-]+$ && "$tag" =~ ^[A-Za-z0-9._-]+$ && "$channel" =~ ^[a-z0-9._-]+$ ]] || { echo "unexpected characters in repository, tag or channel" >&2; exit 2; }
+[[ -n "${RELEASE_SIGNING_KEY:-}" ]] || { echo "RELEASE_SIGNING_KEY is required" >&2; exit 2; }
+
+root="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+version="$(sed -n 's#.*<Version>\(.*\)</Version>.*#\1#p' "$root/backend/Directory.Build.props" | head -1)"
+commit="$(git -C "$root" rev-parse --short=10 HEAD 2>/dev/null || true)"
+built_at="$(date -u +%Y-%m-%dT%H:%M:%SZ)"
+seq="$(date +%s)"
+
+mkdir -p "$outdir"
+printf '{"schema":1,"component":"%s","channel":"%s","image":"%s","digest":"%s","tag":"%s","version":"%s","commit":"%s","built_at":"%s","seq":%s}' \
+  "$component" "$channel" "$repository" "$digest" "$tag" "$version" "$commit" "$built_at" "$seq" > "$outdir/manifest.json"
+
+key="$(mktemp)"
+trap 'rm -f "$key" "$outdir/manifest.sig.bin"' EXIT
+chmod 600 "$key"
+printf '%s\n' "$RELEASE_SIGNING_KEY" > "$key"
+openssl dgst -sha256 -sign "$key" -out "$outdir/manifest.sig.bin" "$outdir/manifest.json"
+base64 -w0 "$outdir/manifest.sig.bin" > "$outdir/manifest.sig" 2>/dev/null || base64 "$outdir/manifest.sig.bin" | tr -d '\n' > "$outdir/manifest.sig"
+echo "signed $component $tag ($digest) seq=$seq"