test: add comprehensive tests for config profile git mounts

- Add git mount merge function tests
- Add profile resolution tests with git mounts
- Add integration tests for CRUD with git mounts
- Add glob expansion tests (patterns, limits, repo boundary)
- Add branch checkout tests (success and failure)
- Add error handling tests for missing repos/invalid UUIDs

All 52 tests pass.

apps/api/tests/conftest.py

@@ -133,6 +133,65 @@ def authenticated_client(test_client) -> Generator[TestClient, None, None]:
     yield test_client
 
 
+@pytest.fixture
+def test_project_and_repo(authenticated_client) -> tuple[str, str]:
+    """Create a project and repository directly in the database."""
+    import uuid
+    from src.models.project import Project
+    from src.models.git_repository import GitRepository
+    
+    project_id = uuid.uuid4()
+    repo_id = uuid.uuid4()
+    user_id = None
+    
+    # Get user ID from session
+    async def get_user_id():
+        nonlocal user_id
+        from src.auth.session import decode_session_cookie
+        settings = Settings()
+        session_cookie = authenticated_client.cookies.get("session")
+        if session_cookie:
+            session = decode_session_cookie(settings=settings, cookie_value=session_cookie)
+            if session:
+                user_id = uuid.UUID(session["user_id"])
+    
+    asyncio.run(get_user_id())
+    
+    if not user_id:
+        raise RuntimeError("Could not get user ID from authenticated client")
+    
+    async def create_project_and_repo():
+        override_fn = app.dependency_overrides.get(get_db_session)
+        if override_fn:
+            gen = override_fn()
+            session = await gen.asend(None)
+            try:
+                project = Project(
+                    id=project_id,
+                    name="test-project",
+                    description="Test project",
+                    owner_id=user_id,
+                )
+                session.add(project)
+                
+                repo = GitRepository(
+                    id=repo_id,
+                    name="test-repo",
+                    path="/tmp/test-repo",
+                    project_id=project_id,
+                    owner_id=user_id,
+                    remote_url="https://github.com/test/repo.git",
+                )
+                session.add(repo)
+                await session.commit()
+            finally:
+                await gen.aclose()
+    
+    asyncio.run(create_project_and_repo())
+    
+    return str(project_id), str(repo_id)
+
+
 @pytest.fixture
 def admin_client(test_client) -> Generator[TestClient, None, None]:
     """Provide an authenticated test client with an admin user."""