feat: add live camera multi-device viewer mode

client/src/lib/changelog.ts

@@ -8,6 +8,28 @@ export type ChangeLogEntry = {
 };
 
 export const CHANGE_LOG_ENTRIES: ChangeLogEntry[] = [
+  {
+    version: "2026.03.16-live-camera-multidevice-viewer",
+    releaseDate: "2026-03-16",
+    repoVersion: "f0bbe4c",
+    summary: "实时分析新增同账号多端互斥和同步观看模式，分析持有端独占摄像头，其它端只能查看同步画面与核心识别结果。",
+    features: [
+      "同一账号在 `/live-camera` 进入实时分析后，会写入按用户维度的 runtime 锁，其他设备不能重复启动摄像头或分析",
+      "其他设备会自动进入“同步观看模式”，可订阅持有端的实时画面，并同步看到动作、评分、反馈、最近片段和归档段数",
+      "同步观看复用 media 服务的 WebRTC viewer 通道，传输的是带骨架、关键点和虚拟形象覆盖后的合成画面",
+      "runtime 锁按 session sid 区分持有端，兼容缺少 sid 的旧 token，超过 15 秒无心跳会自动判定为陈旧并释放",
+      "线上 smoke 已确认 `https://te.hao.work/live-camera` 当前仍在旧前端构建，公开站点资源 revision 还是 `index-BWEXNszf.js` / `index-BL6GQzUF.css`，本地新构建产物为 `index-BmsO49OJ.js`",
+    ],
+    tests: [
+      "pnpm check",
+      "pnpm exec vitest run server/features.test.ts",
+      "go test ./... && go build ./... (media)",
+      "pnpm build",
+      "pnpm exec playwright test tests/e2e/app.spec.ts --grep \"live camera\"",
+      "pnpm exec playwright test tests/e2e/app.spec.ts --grep \"recorder flow archives a session and exposes it in videos\"",
+      "curl -I https://te.hao.work/live-camera",
+    ],
+  },
   {
     version: "2026.03.16-live-analysis-overlay-archive",
     releaseDate: "2026-03-16",

client/src/lib/media.ts

@@ -50,6 +50,7 @@ export type MediaSession = {
   previewUpdatedAt?: string;
   streamConnected: boolean;
   lastStreamAt?: string;
+  viewerCount?: number;
   playback: {
     webmUrl?: string;
     mp4Url?: string;
@@ -122,6 +123,14 @@ export async function signalMediaSession(sessionId: string, payload: { sdp: stri
   });
 }
 
+export async function signalMediaViewerSession(sessionId: string, payload: { sdp: string; type: string }) {
+  return request<{ viewerId: string; sdp: string; type: string }>(`/sessions/${sessionId}/viewer-signal`, {
+    method: "POST",
+    headers: { "Content-Type": "application/json" },
+    body: JSON.stringify(payload),
+  });
+}
+
 export async function uploadMediaSegment(
   sessionId: string,
   sequence: number,