test: P2测试覆盖 — user/pool/schema_drift端点 43个新测试 (895→1017全通过)

新增测试文件:
- test_user_endpoint.py (18 tests): 用户CRUD/列表过滤/权限控制/自删保护
- test_pool_endpoint.py (12 tests): 连接池状态/重置/概览/mock外部依赖
- test_schema_drift_endpoint.py (13 tests): Schema快照捕获/漂移检测/历史查询

覆盖率提升:
- user端点: 0→18 tests (CRUD+权限+重复用户名+自删保护)
- pool端点: 0→12 tests (stats/reset/overview+角色访问控制)
- schema_drift端点: 0→13 tests (capture/check/history+dict序列化兼容)

修复: run.sh启动脚本同步

backend/tests/test_pool_endpoint.py

@@ -0,0 +1,186 @@
+"""连接池管理 API 端点测试。"""
+import pytest
+from unittest.mock import patch, MagicMock, AsyncMock
+from httpx import AsyncClient
+
+from app.models.user import User
+from app.models.instance import Instance
+from app.core.security import hash_password, create_access_token
+
+
+def auth_header(token: str) -> dict:
+    return {"Authorization": f"Bearer {token}"}
+
+
+@pytest.mark.asyncio
+class TestPoolStats:
+    """GET /api/v1/pools/instances/{instance_id}/stats"""
+
+    async def test_pool_stats_initialized(
+        self, client: AsyncClient, admin_token: str, test_instance
+    ):
+        mock_stats = MagicMock()
+        mock_stats.to_dict.return_value = {
+            "instance_id": test_instance.id,
+            "status": "active",
+            "total_connections": 5,
+            "active_connections": 2,
+            "idle_connections": 3,
+        }
+        with patch(
+            "app.api.v1.endpoints.pool.get_pool_manager"
+        ) as mock_mgr:
+            mock_mgr.return_value.get_pool_stats.return_value = mock_stats
+            resp = await client.get(
+                f"/api/v1/pools/instances/{test_instance.id}/stats",
+                headers=auth_header(admin_token),
+            )
+        assert resp.status_code == 200
+        data = resp.json()
+        assert data["status"] == "active"
+        assert data["total_connections"] == 5
+
+    async def test_pool_stats_not_initialized(
+        self, client: AsyncClient, admin_token: str, test_instance
+    ):
+        with patch(
+            "app.api.v1.endpoints.pool.get_pool_manager"
+        ) as mock_mgr:
+            mock_mgr.return_value.get_pool_stats.return_value = None
+            resp = await client.get(
+                f"/api/v1/pools/instances/{test_instance.id}/stats",
+                headers=auth_header(admin_token),
+            )
+        assert resp.status_code == 200
+        data = resp.json()
+        assert data["status"] == "not_initialized"
+
+    async def test_pool_stats_instance_not_found(
+        self, client: AsyncClient, admin_token: str
+    ):
+        resp = await client.get(
+            "/api/v1/pools/instances/9999/stats",
+            headers=auth_header(admin_token),
+        )
+        assert resp.status_code == 404
+
+    async def test_pool_stats_forbidden_developer(
+        self, client: AsyncClient, developer_token: str, test_instance
+    ):
+        resp = await client.get(
+            f"/api/v1/pools/instances/{test_instance.id}/stats",
+            headers=auth_header(developer_token),
+        )
+        assert resp.status_code == 403
+
+    async def test_pool_stats_dba_allowed(
+        self, client: AsyncClient, dba_token: str, test_instance
+    ):
+        with patch(
+            "app.api.v1.endpoints.pool.get_pool_manager"
+        ) as mock_mgr:
+            mock_mgr.return_value.get_pool_stats.return_value = None
+            resp = await client.get(
+                f"/api/v1/pools/instances/{test_instance.id}/stats",
+                headers=auth_header(dba_token),
+            )
+        assert resp.status_code == 200
+
+
+@pytest.mark.asyncio
+class TestResetPool:
+    """POST /api/v1/pools/instances/{instance_id}/reset"""
+
+    async def test_reset_pool_success(
+        self, client: AsyncClient, admin_token: str, test_instance
+    ):
+        with patch(
+            "app.api.v1.endpoints.pool.get_pool_manager"
+        ) as mock_mgr:
+            mock_mgr.return_value.reset_pool = AsyncMock()
+            resp = await client.post(
+                f"/api/v1/pools/instances/{test_instance.id}/reset",
+                headers=auth_header(admin_token),
+            )
+        assert resp.status_code == 200
+        data = resp.json()
+        assert "已重置" in data["message"]
+        assert data["instance_id"] == test_instance.id
+
+    async def test_reset_pool_dba_allowed(
+        self, client: AsyncClient, dba_token: str, test_instance
+    ):
+        with patch(
+            "app.api.v1.endpoints.pool.get_pool_manager"
+        ) as mock_mgr:
+            mock_mgr.return_value.reset_pool = AsyncMock()
+            resp = await client.post(
+                f"/api/v1/pools/instances/{test_instance.id}/reset",
+                headers=auth_header(dba_token),
+            )
+        assert resp.status_code == 200
+
+    async def test_reset_pool_forbidden_developer(
+        self, client: AsyncClient, developer_token: str, test_instance
+    ):
+        resp = await client.post(
+            f"/api/v1/pools/instances/{test_instance.id}/reset",
+            headers=auth_header(developer_token),
+        )
+        assert resp.status_code == 403
+
+
+@pytest.mark.asyncio
+class TestPoolsOverview:
+    """GET /api/v1/pools/overview"""
+
+    async def test_pools_overview_empty(
+        self, client: AsyncClient, admin_token: str
+    ):
+        with patch(
+            "app.api.v1.endpoints.pool.get_pool_manager"
+        ) as mock_mgr:
+            mock_mgr.return_value.get_all_stats.return_value = {}
+            resp = await client.get(
+                "/api/v1/pools/overview",
+                headers=auth_header(admin_token),
+            )
+        assert resp.status_code == 200
+        data = resp.json()
+        assert data["total_pools"] == 0
+        assert data["pools"] == []
+
+    async def test_pools_overview_with_pools(
+        self, client: AsyncClient, admin_token: str
+    ):
+        mock_stats = MagicMock()
+        mock_stats.to_dict.return_value = {
+            "instance_id": 1,
+            "status": "active",
+            "total_connections": 10,
+        }
+        with patch(
+            "app.api.v1.endpoints.pool.get_pool_manager"
+        ) as mock_mgr:
+            mock_mgr.return_value.get_all_stats.return_value = {1: mock_stats}
+            resp = await client.get(
+                "/api/v1/pools/overview",
+                headers=auth_header(admin_token),
+            )
+        assert resp.status_code == 200
+        data = resp.json()
+        assert data["total_pools"] == 1
+        assert len(data["pools"]) == 1
+
+    async def test_pools_overview_unauthorized(self, client: AsyncClient):
+        resp = await client.get("/api/v1/pools/overview")
+        assert resp.status_code == 401
+
+    async def test_pools_overview_forbidden_guest(
+        self, client: AsyncClient, guest_token: str
+    ):
+        resp = await client.get(
+            "/api/v1/pools/overview",
+            headers=auth_header(guest_token),
+        )
+        assert resp.status_code == 403