feat(jobs): echo worker + CLI bootstrap

Job queue starts only in the CLI gate (not inside createApp), so tests
manage their own queue lifecycle. waitForJob() takes a (name, id) pair
to match pg-boss v10's getJobById signature.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

tests/jobs/workers/echo.test.js

@@ -0,0 +1,22 @@
+import { describe, it, expect, beforeEach, afterEach } from 'vitest';
+import { resetDb } from '../../helpers/db.js';
+import { migrateUp } from '../../../lib/db/migrate.js';
+import { stopBoss, waitForJob } from '../../helpers/boss.js';
+import * as queue from '../../../lib/jobs/queue.js';
+import { registerWorkers } from '../../../lib/jobs/index.js';
+
+beforeEach(async () => {
+  await resetDb(); await migrateUp();
+  await queue.start();
+  await registerWorkers();
+});
+afterEach(async () => { await stopBoss(); });
+
+describe('echo worker', () => {
+  it('completes with the expected output', async () => {
+    const id = await queue.enqueue('echo', { ping: 7 });
+    const j = await waitForJob('echo', id);
+    expect(j.state).toBe('completed');
+    expect(j.output).toEqual({ pong: 7 });
+  });
+});