add health check endpoint

tests/test_health.py

@@ -0,0 +1,9 @@
+# SPDX-FileCopyrightText: 2026 Filmhuis Den Haag
+# SPDX-License-Identifier: AGPL-3.0-or-later
+
+from fastapi.testclient import TestClient
+
+
+def test_health(client: TestClient):
+    response = client.get("/health")
+    assert response.status_code == 200