feat(server): wire PgEventBus and event-driven settings cache into process assembly

main.ts starts the PG-backed SSE bus (api/worker processes now see each other's events)
and stops it on shutdown; bootstrap passes ctx.events to the settings reader so
settings.changed invalidates every process's cache.

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

apps/server/src/main.ts

@@ -5,7 +5,7 @@ import denoJson from "../deno.json" with { type: "json" };
 import { loadConfig } from "./config.ts";
 import { bootstrap } from "./context.ts";
 import { createApp } from "./http/app.ts";
-import { EventBus } from "./http/sse.ts";
+import { PgEventBus } from "./http/sse-pg.ts";
 import { createLogger } from "./logger.ts";
 import { SERVER_MODULES } from "./modules/index.ts";
 import { runPreflight } from "./preflight.ts";
@@ -73,7 +73,19 @@ if (role === "migrate" || role === "preflight") {
   Deno.exit(code);
 }
 
-const bus = new EventBus();
+// SSE 总线:sse_event 表 + LISTEN/NOTIFY,api 与 worker 分进程时事件互相可见
+let bus: PgEventBus;
+try {
+  bus = await PgEventBus.start({
+    db,
+    connectionString: config.DATABASE_URL,
+    logger: logger.child({ component: "sse-bus" }),
+  });
+} catch (err) {
+  logger.error({ err }, "SSE 总线启动失败");
+  await db.destroy();
+  Deno.exit(1);
+}
 const stops: Array<() => Promise<void>> = [];
 
 // 装配 ServerContext:模块注册任务/能力,连接任务引擎(api 角色也要:入队、信号、取消)
@@ -138,6 +150,7 @@ async function shutdown(signal: Deno.Signal) {
   const force = setTimeout(() => Deno.exit(1), 10_000);
   await Promise.allSettled(stops.map((s) => s()));
   await engine.stop().catch((err) => logger.error({ err }, "任务引擎关闭失败"));
+  await bus.stop().catch(() => {});
   await db.destroy();
   clearTimeout(force);
   Deno.exit(0);