feat(wallet): 钱包系统替代配额系统，新增支付与退款机制

- 新增钱包余额管理、充值、扣费、退款完整流程
- 新增支付网关抽象层（支持手动/支付宝/微信）
- 用量计费从配额系统迁移到钱包余额扣费
- 新增管理员钱包管理与支付订单管理页面
- 新增用户钱包中心页面
- 移除独立 Key 锁定机制，统一由钱包余额控制
- 新增相关 API 路由、序列化器与数据库迁移
- 新增钱包、支付、退款相关测试

tests/services/test_usage_queue_events.py

@@ -1304,6 +1304,9 @@ async def test_record_usage_batch_updates_when_status_completed_billing_pending(
         def filter(self, *args: Any, **kwargs: Any) -> "DummyQuery":
             return self
 
+        def with_for_update(self) -> "DummyQuery":
+            return self
+
         def all(self) -> list[Any]:
             return self._all_result
 
@@ -1362,10 +1365,10 @@ async def test_record_usage_batch_updates_when_status_completed_billing_pending(
 
 
 @pytest.mark.asyncio
-async def test_record_usage_batch_uses_bulk_insert_mappings_for_new_records(
+async def test_record_usage_batch_uses_orm_insert_for_new_records(
     monkeypatch: Any,
 ) -> None:
-    """确保批量新建 Usage 走 bulk_insert_mappings。"""
+    """确保批量新建 Usage 走 ORM add 路径，以便复用统一结算逻辑。"""
 
     from src.models.database import Usage
     from src.services.usage.service import UsageService
@@ -1380,27 +1383,18 @@ async def test_record_usage_batch_uses_bulk_insert_mappings_for_new_records(
         def filter(self, *args: Any, **kwargs: Any) -> "DummyQuery":
             return self
 
+        def with_for_update(self) -> "DummyQuery":
+            return self
+
         def all(self) -> list[Any]:
             return self._all_result
 
-    inserted = Usage(
-        request_id="req-usage-batch-new",
-        provider_name="openai",
-        model="gpt-4",
-        status="completed",
-        billing_status="settled",
-    )
-
     usage_query_calls = {"count": 0}
 
     def _query_side_effect(model: Any) -> Any:
         if model is Usage:
             usage_query_calls["count"] += 1
-            if usage_query_calls["count"] == 1:
-                # existing_records
-                return DummyQuery([])
-            # inserted_records
-            return DummyQuery([inserted])
+            return DummyQuery([])
         return DummyQuery([])
 
     db = MagicMock()
@@ -1431,13 +1425,10 @@ async def test_record_usage_batch_uses_bulk_insert_mappings_for_new_records(
         ],
     )
 
-    db.bulk_insert_mappings.assert_called_once()
-    args, _kwargs = db.bulk_insert_mappings.call_args
-    assert args[0] is Usage
-    mappings = args[1]
-    assert isinstance(mappings, list) and len(mappings) == 1
-    assert mappings[0]["request_id"] == "req-usage-batch-new"
-    assert mappings[0]["billing_status"] == "settled"
-    assert mappings[0].get("finalized_at") is not None
+    db.add.assert_called_once()
+    db.bulk_insert_mappings.assert_not_called()
 
-    assert result and result[0] is inserted
+    assert result and isinstance(result[0], Usage)
+    assert result[0].request_id == "req-usage-batch-new"
+    assert result[0].billing_status == "settled"
+    assert result[0].finalized_at is not None