feat: add reusable jobqueue library

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

tests/SqliteStorage.test.ts

@@ -0,0 +1,76 @@
+import { SqliteStorage } from '../src/index.js';
+import { cleanupDir, createDbPath, createTempDir } from './helpers.js';
+
+describe('SqliteStorage', () => {
+  it('creates, updates, and completes jobs', () => {
+    const dir = createTempDir();
+    const storage = new SqliteStorage<{ url: string }>(createDbPath(dir));
+
+    try {
+      const job = storage.createJob(
+        'job-1',
+        { url: 'https://example.com' },
+        [
+          {
+            name: 'download',
+            status: 'pending',
+            progress: 0,
+            message: null,
+            startedAt: null,
+            completedAt: null,
+            error: null,
+          },
+        ],
+        {},
+        3,
+      );
+
+      expect(job.status).toBe('pending');
+      expect(storage.claimPendingJob(job.id)).toBe(true);
+
+      const inProgress = storage.saveProgress(
+        job.id,
+        'download',
+        [
+          {
+            name: 'download',
+            status: 'active',
+            progress: 50,
+            message: 'halfway',
+            startedAt: new Date().toISOString(),
+            completedAt: null,
+            error: null,
+          },
+        ],
+        50,
+        'halfway',
+      );
+
+      expect(inProgress.status).toBe('active');
+      expect(inProgress.progress).toBe(50);
+
+      const completed = storage.completeJob(
+        job.id,
+        [
+          {
+            name: 'download',
+            status: 'completed',
+            progress: 100,
+            message: null,
+            startedAt: new Date().toISOString(),
+            completedAt: new Date().toISOString(),
+            error: null,
+          },
+        ],
+        { download: { filePath: '/tmp/file' } },
+      );
+
+      expect(completed.status).toBe('completed');
+      expect(completed.progress).toBe(100);
+      expect(completed.phaseResults.download).toEqual({ filePath: '/tmp/file' });
+    } finally {
+      storage.close();
+      cleanupDir(dir);
+    }
+  });
+});