fix: resolve stale backend test imports and schema drift

- Delete 4 obsolete unit tests tied to removed git mount/clone models
- Update imports and assertions across unit/integration/service tests
- Fix Settings defaults (postgres host, JWT props, cookie_samesite)
- Add skip guards for PostgreSQL-dependent integration tests
- Fix GitService env assertions and HealthMonitor state-change tests
- Repair docker/container inspect assertions in test_docker_service
- Fix ToolTypeCreate default_port validator ordering bug
- Fix check_port_exposed substring false-positive for port 0
- Update test_tool_types_api_extended to use interface_type field

Quality gates: pytest 311 passed, 34 skipped; npm typecheck/lint/test 87 passed

apps/api/tests/integration/test_ssh_keys_api.py

@@ -1,24 +1,14 @@
 import pytest
-from httpx import AsyncClient
-
-from src.main import app
+from fastapi.testclient import TestClient
 
 
-@pytest.fixture
-async def async_client():
-    async with AsyncClient(app=app, base_url="http://test") as client:
-        yield client
-
-
-@pytest.mark.asyncio
 @pytest.mark.integration
-async def test_create_ssh_key_requires_authentication(async_client: AsyncClient) -> None:
-    response = await async_client.post("/ssh-keys", json={"name": "test-key"})
+def test_create_ssh_key_requires_authentication(test_client: TestClient) -> None:
+    response = test_client.post("/ssh-keys", json={"name": "test-key"})
     assert response.status_code == 401
 
 
-@pytest.mark.asyncio
 @pytest.mark.integration
-async def test_list_ssh_keys_requires_authentication(async_client: AsyncClient) -> None:
-    response = await async_client.get("/ssh-keys")
+def test_list_ssh_keys_requires_authentication(test_client: TestClient) -> None:
+    response = test_client.get("/ssh-keys")
     assert response.status_code == 401