feat: 强化用量计费状态机，新增钱包每日消费汇总分类账

- 将 usage.billing_status 默认值从 settled 改为 pending，完善
  pending -> settled/void 的状态转换逻辑，确保终态不可逆
- 新增 WalletDailyUsageLedger 模型和聚合服务，按账单日汇总
  每个钱包的消费金额、请求数和 token 用量
- 前端钱包中心页面集成每日消费流水展示，支持与充值记录混合
  排序和分页
- 新增两个数据库迁移：修复历史数据状态一致性、创建每日汇总表
- 补充计费状态机单元测试

Closes #218

Co-authored-by: LewisPen <LewisPen@nyadoo.com>

tests/services/test_usage_queue_events.py

@@ -378,6 +378,7 @@ async def test_event_to_record_body_deserialization(monkeypatch: Any) -> None:
     event = build_usage_event(
         event_type=UsageEventType.COMPLETED,
         request_id="req-body-test",
+        timestamp_ms=1_700_000_000_123,
         data={
             "user_id": "user-1",
             "api_key_id": "key-1",
@@ -396,6 +397,7 @@ async def test_event_to_record_body_deserialization(monkeypatch: Any) -> None:
     assert record["request_body"]["messages"][0]["content"] == "hello"
     assert isinstance(record["response_body"], dict)
     assert record["response_body"]["choices"][0]["message"]["content"] == "hi"
+    assert record["finalized_at"] is not None
 
 
 @pytest.mark.asyncio

tests/services/test_usage_state_machine.py

@@ -0,0 +1,85 @@
+from types import SimpleNamespace
+from typing import Any
+from unittest.mock import MagicMock
+
+import pytest
+from fastapi import HTTPException
+
+from src.services.task.video.cancel import VideoTaskCancelService
+from src.services.usage.service import UsageService
+
+
+class _DummyQuery:
+    def __init__(self, obj: Any) -> None:
+        self._obj = obj
+
+    def filter(self, *args: Any, **kwargs: Any) -> "_DummyQuery":
+        return self
+
+    def with_for_update(self) -> "_DummyQuery":
+        return self
+
+    def first(self) -> Any:
+        return self._obj
+
+
+def test_update_settled_billing_rejects_terminal_usage() -> None:
+    usage = SimpleNamespace(
+        request_id="req-1",
+        billing_status="settled",
+        finalized_at="2026-03-06T00:00:00+00:00",
+        total_cost_usd=1.23,
+    )
+    db = MagicMock()
+    db.query.return_value = _DummyQuery(usage)
+
+    updated = UsageService.update_settled_billing(
+        db,
+        request_id="req-1",
+        total_cost_usd=2.34,
+        status="completed",
+    )
+
+    assert updated is False
+    assert usage.total_cost_usd == 1.23
+
+
+def test_update_usage_status_skips_terminal_usage() -> None:
+    usage = SimpleNamespace(
+        request_id="req-1",
+        billing_status="settled",
+        finalized_at="2026-03-06T00:00:00+00:00",
+        status="completed",
+        error_message=None,
+        provider_name="demo",
+    )
+    db = MagicMock()
+    db.query.return_value = _DummyQuery(usage)
+
+    result = UsageService.update_usage_status(
+        db=db,
+        request_id="req-1",
+        status="failed",
+        error_message="boom",
+    )
+
+    assert result is usage
+    assert usage.status == "completed"
+    assert usage.error_message is None
+    db.commit.assert_not_called()
+
+
+@pytest.mark.asyncio
+async def test_task_cancel_rejects_terminal_task() -> None:
+    task = SimpleNamespace(
+        id="t1",
+        user_id="u1",
+        status="completed",
+        request_id="req-1",
+    )
+    svc = VideoTaskCancelService(MagicMock())
+
+    with pytest.raises(HTTPException) as exc:
+        await svc.cancel_task(task=task, task_id="t1")
+
+    assert exc.value.status_code == 409

tests/services/test_video_finalize.py

@@ -54,8 +54,8 @@ def _make_db() -> MagicMock:
     usage_obj = SimpleNamespace(
         id="usage-1",
         request_id="req-1",
-        billing_status="settled",  # finalize_submitted already settled
-        request_metadata=None,  # no billing_updated_at yet
+        billing_status="pending",
+        request_metadata=None,
     )
 
     q_usage = MagicMock()

tests/services/test_video_task_poller.py

@@ -48,3 +48,33 @@ async def test_poll_task_status_routes_gemini_video_to_gemini(
     assert result.status == VideoStatus.PROCESSING
     assert poll_gemini.await_count == 1
     assert poll_openai.await_count == 0
+
+
+@pytest.mark.asyncio
+async def test_update_task_after_poll_skips_terminal_cancelled_task(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    finalize = AsyncMock()
+    adapter = VideoTaskPollerAdapter(finalize_video_task_fn=finalize)
+
+    cancelled_task = SimpleNamespace(
+        id="t1",
+        status=VideoStatus.CANCELLED.value,
+    )
+
+    session = MagicMock()
+    session.__enter__.return_value = session
+    session.__exit__.return_value = None
+    session.get.return_value = cancelled_task
+
+    monkeypatch.setattr("src.services.task.video.poller_adapter.create_session", lambda: session)
+
+    await adapter.update_task_after_poll(
+        task_id="t1",
+        result=InternalVideoPollResult(status=VideoStatus.COMPLETED),
+        ctx=None,
+        redis_client=None,
+    )
+
+    finalize.assert_not_awaited()
+    session.commit.assert_not_called()