fix(tasks): align OutboxRelay with outbox_event status/next_attempt_at/idempotency_key

The relay only looked at published_at and ignored the ADR-002 §2.1 columns
added in db 0002_foundation: rows stayed status='pending' forever after
dispatch, failures were retried every tick without backoff, and the
row-level idempotency_key was never used as the engine enqueue key.

- claim status='pending' AND next_attempt_at<=now()
- enqueue with idempotency_key (fallback outbox:<id>)
- success: status=dispatched, published_at, attempts+1
- failure: attempts+1, exponential backoff (cap 5 min), last_error; dead at maxAttempts
- test helper table now mirrors db 0001+0002; tests cover backoff and dead

Co-Authored-By: Claude Fable 5.1 <[email protected]>

packages/tasks/test/outbox.test.ts

@@ -74,8 +74,13 @@ describe.skipIf(!hasPg)("OutboxRelay", () => {
     expect(calls).toHaveLength(60);
     expect(new Set(calls).size).toBe(60);
 
-    const pending = await sql<{ type: string }>`SELECT type FROM outbox_event WHERE published_at IS NULL`.execute(db);
+    const pending = await sql<{ type: string }>`SELECT type FROM outbox_event WHERE status = 'pending'`.execute(db);
     expect(pending.rows).toEqual([{ type: "other.type" }]); // 未配置路由的 type 不认领
+    const dispatched = await sql<{ n: string }>`
+      SELECT count(*) n FROM outbox_event WHERE status = 'dispatched' AND published_at IS NOT NULL AND attempts = 1`.execute(
+      db,
+    );
+    expect(dispatched.rows[0]!.n).toBe("60");
 
     const runs = await sql<{ n: string; keys: string }>`
       SELECT count(*) n, count(DISTINCT idempotency_key) keys FROM tasks_run_meta WHERE task_name = 'echo'`.execute(db);
@@ -98,8 +103,27 @@ describe.skipIf(!hasPg)("OutboxRelay", () => {
       logSink: () => {},
     });
     expect(await relay.pollOnce()).toEqual({ published: 0, failed: 1 });
-    const left = await sql<{ n: string }>`
-      SELECT count(*) n FROM outbox_event WHERE published_at IS NULL AND type = 'echo.requested'`.execute(db);
-    expect(left.rows[0]!.n).toBe("1");
+    const left = await sql<{ status: string; attempts: number; backoff: boolean; err: string }>`
+      SELECT status, attempts, next_attempt_at > now() backoff, last_error->>'message' err FROM outbox_event
+      WHERE published_at IS NULL AND type = 'echo.requested'`.execute(db);
+    expect(left.rows).toHaveLength(1);
+    expect(left.rows[0]).toMatchObject({ status: "pending", attempts: 1, backoff: true });
+    // 退避期内不再认领;到期后再失败达到上限置 dead
+    expect(await relay.pollOnce()).toEqual({ published: 0, failed: 0 });
+    await sql`UPDATE outbox_event SET next_attempt_at = now() WHERE type = 'echo.requested' AND published_at IS NULL`.execute(
+      db,
+    );
+    const strict = new OutboxRelay({
+      db,
+      engine,
+      routes: { "echo.requested": (ev) => ({ task: "echo", input: ev.payload }) },
+      logSink: () => {},
+      maxAttempts: 2,
+    });
+    expect(await strict.pollOnce()).toEqual({ published: 0, failed: 1 });
+    const dead = await sql<{
+      status: string;
+    }>`SELECT status FROM outbox_event WHERE type = 'echo.requested' AND published_at IS NULL`.execute(db);
+    expect(dead.rows).toEqual([{ status: "dead" }]);
   });
 });