fix(worker): break circular import by extracting PgBoss singleton

incremental-sync.ts and api/cw/sync.ts imported getBoss() from workert.ts.
When workert.ts (the entry point) dynamically imported incremental-sync.ts,
it triggered a circular module re-evaluation that hung indefinitely.

Extract the PgBoss singleton and getBoss() factory to a new boss-instance.ts
module that neither has top-level async side-effects nor imports from
workert.ts. All consumers (workert.ts, index.ts, incremental-sync.ts,
cw/sync.ts) now import from boss-instance.ts instead.

api/src/workert.ts

@@ -1,29 +1,7 @@
-import { PgBoss } from "pg-boss";
 import { io, Socket } from "socket.io-client";
 import { WorkerQueue } from "./modules/workers/queues";
 import { setupEventDebugger } from "./modules/logging/eventDebugger";
-
-// Add statement and connection timeouts to prevent silent hangs
-function makePgBossUrl(rawUrl: string): string {
-  try {
-    const u = new URL(rawUrl);
-    // 30-second statement timeout and 15-second TCP connect timeout
-    u.searchParams.set("options", "-c statement_timeout=30000");
-    u.searchParams.set("connect_timeout", "15");
-    return u.toString();
-  } catch {
-    return rawUrl;
-  }
-}
-
-const boss = new PgBoss({
-  connectionString: makePgBossUrl(process.env.DATABASE_URL!),
-  connectionTimeoutMillis: 15_000,
-});
-
-boss.on("error", (err) => {
-  console.error("[worker] PgBoss error", err);
-});
+import { boss, getBoss } from "./boss-instance";
 
 let bossStartPromise: Promise<void> | null = null;
 let reservationQueueReady = false;
@@ -160,14 +138,6 @@ export async function initializeWorkerSystem(): Promise<void> {
   console.log("[worker] Worker system initialized - ready for job enqueueing");
 }
 
-/**
- * Get the PgBoss instance for direct job enqueueing.
- * Must call initializeWorkerSystem() first.
- */
-export function getBoss(): PgBoss {
-  return boss;
-}
-
 if (import.meta.main) {
   // if (Bun.env.NODE_ENV === "development") {
   //   setupEventDebugger({ processLabel: "WORKER" });