feat(tasks,server,web): bridge outbox events to the SSE bus (U3)

OutboxRelay gains a `mirror` option: listed types are claimed even without a
task route and, after the claim transaction commits, published in order to
the realtime bus (publish failures are logged, delivery state unaffected).
The worker mirrors feed.*, decision.*, download.*, organization.* and
subscription.* (feed.due excluded) with their business-id payloads, so the
home page, inbox, task stream and feed tables finally receive them. Feed
tables refresh on feed.fetched / feed.health_changed; the task stream also
listens to feed and decision events.

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

apps/web/app/components/tasks/task-stream.tsx

@@ -29,12 +29,16 @@ import {
 
 export type StreamTab = "all" | "active" | "failed";
 
-/** 引擎本身不发事件;业务事件足以代表任务在动,2 秒节流刷新 */
+/** 引擎本身不发事件;业务事件(outbox → SSE 桥)足以代表任务在动,2 秒节流刷新 */
 const TASK_EVENTS = [
   "task.created",
   "task.status_changed",
   "download.status_changed",
+  "download.threshold",
   "organization.changed",
+  "feed.fetched",
+  "decision.created",
+  "decision.updated",
   "agent.run_status",
   "schedule.changed",
 ];