fix(core): add timeout to BackgroundProcessManager.close()

close() hangs forever when jobs depend on unavailable resources
(e.g. network down during DataStore subscription teardown).

Race _closingPromise against a 10s timeout so it always resolves.

Author: anivar

packages/core/__tests__/BackgroundProcessManager.test.ts

@@ -664,4 +664,21 @@ describe('BackgroundProcessManager', () => {
 		unblock?.();
 		await close;
 	});
+
+	test('close() resolves after timeout even if jobs never complete', async () => {
+		const manager = new BackgroundProcessManager();
+
+		manager.add(
+			() => new Promise<void>(() => {}),
+			'hanging job',
+		);
+
+		const start = Date.now();
+		await manager.close();
+		const elapsed = Date.now() - start;
+
+		expect(manager.isClosed).toBe(true);
+		// should resolve around the 10s internal timeout, not hang forever
+		expect(elapsed).toBeLessThan(15_000);
+	}, 20_000);
 });

packages/core/src/BackgroundProcessManager/BackgroundProcessManager.ts

@@ -389,7 +389,19 @@ export class BackgroundProcessManager {
 				Array.from(this.jobs).map(j => j.promise),
 			);
 
+			const CLOSE_TIMEOUT_MS = 10_000;
+			let timer: ReturnType<typeof setTimeout>;
+			const timeoutPromise = new Promise<PromiseSettledResult<any>[]>(
+				resolve => {
+					timer = setTimeout(() => resolve([]), CLOSE_TIMEOUT_MS);
+				},
+			);
+			this._closingPromise = Promise.race([
+				this._closingPromise,
+				timeoutPromise,
+			]);
 			await this._closingPromise;
+			clearTimeout(timer!);
 			this._state = BackgroundProcessManagerState.Closed;
 		}