fix(system): retired heartbeat rows no longer alarm on status page

- GET /system/health splits processes into current instances (hosts with
  a beat in the last 10 min, newest per host+kind, not stopped) and
  retiredProcesses[]; 45s stale and level only consider current ones
- heartbeat writer marks stopped_at on graceful exit (migration 0043),
  upsert clears it; pure api role now stops its writer on SIGTERM
- scheduled job system.heartbeat_cleanup (maintain, 1h) deletes rows
  without a beat for 24h and samples older than 7 days
- status page: per-role alarms ("io worker 45 秒没有心跳"), collapsible
  retired instances; glossary/runbook updated
- bump all members to 0.2.2, CHANGELOG [0.2.2]

Co-Authored-By: Claude Opus 5.5 <[email protected]>

apps/server/src/main.ts

@@ -237,6 +237,11 @@ if (role === "api" || role === "all") {
     ac.abort();
     await server.finished;
   });
+  if (role === "api") {
+    // 纯 api 进程不走 worker 的模块 stop:这里停 system 模块的心跳写入器,把本进程的心跳行标 stopped_at
+    const sys = SERVER_MODULES.find((m) => m.name === "system");
+    if (sys?.stop) stops.push(async () => await sys.stop?.());
+  }
 }
 if (role === "worker" || role === "worker:agent" || role === "all") {
   const worker = await startWorker({