🧪 Add tests for saved searches API endpoints

Added a new test file `tests/test_api_saved_searches.py` containing a comprehensive test suite for the CRUD operations provided in `app/api/saved_searches.py`. The suite validates happy paths, error conditions (like missing filters, name limits, duplicates), and user isolation using an in-memory SQLite database.

Co-authored-by: christianlouis <361235+christianlouis@users.noreply.github.com>

fix_test7.py

@@ -0,0 +1,53 @@
+import re
+
+with open("tests/test_api_saved_searches.py", "r") as f:
+    content = f.read()
+
+# We need to mock get_current_user in app.api.saved_searches (which is imported from app.auth)
+# because saved searches uses `_get_user_id` which calls `get_current_user(request)`.
+# But `_get_user_id` is NOT a dependency injected via `Depends`!
+# Let's verify `app/api/saved_searches.py` uses `Depends` or just calls it.
+
+# In `app/api/saved_searches.py`:
+# def _get_user_id(request: Request) -> str:
+#     user = get_current_user(request)
+#     if user:
+#         return user.get("preferred_username") ...
+# It's called directly inside the routes: `user_id = _get_user_id(request)`
+# It doesn't use `Depends(_get_user_id)`.
+# Ah! But earlier I saw `_get_user_id` wasn't mocked properly. Let's use patch to mock `_get_user_id`.
+
+# Wait, `TestClient` can be given an active session, but `app.auth.get_current_user` uses `request.session.get("user")` or Bearer token.
+# Is `AUTH_ENABLED` false? The test env has `os.environ["AUTH_ENABLED"] = "False"` in `tests/conftest.py`.
+# If `AUTH_ENABLED` is false, `require_login` is a no-op, and `_get_user_id` falls back to "anonymous".
+# Actually, `_get_user_id` returns "anonymous" if `get_current_user(request)` is None.
+# If `_OWNER` is "test_user@example.com", we should probably just patch `_get_user_id`.
+
+replacement = """def _make_client(int_engine, owner_id: str = _OWNER):
+    \"\"\"Return a TestClient with *owner_id* injected as the authenticated user.\"\"\"
+    from app.main import app
+    from unittest.mock import patch
+
+    def override_db():
+        Session = sessionmaker(bind=int_engine)
+        session = Session()
+        try:
+            yield session
+        finally:
+            session.close()
+
+    app.dependency_overrides[get_db] = override_db
+    with patch("app.api.saved_searches._get_user_id", return_value=owner_id):
+        with TestClient(app, base_url="http://localhost", raise_server_exceptions=False) as client:
+            yield client
+    app.dependency_overrides.clear()"""
+
+content = re.sub(
+    r"def _make_client\(int_engine, owner_id: str = _OWNER\):.*?(?=@pytest\.fixture\(\)\ndef int_client\(int_engine\):)",
+    replacement + "\n\n\n",
+    content,
+    flags=re.DOTALL
+)
+
+with open("tests/test_api_saved_searches.py", "w") as f:
+    f.write(content)