Harden registry API and schema validation

tests/test_registry.py

@@ -143,6 +143,8 @@ def test_registry_http_service_serves_queries(tmp_path: Path) -> None:
 
         with urllib.request.urlopen(f"{base_url}/health", timeout=5) as response:
             assert json.loads(response.read())["status"] == "ok"
+        with urllib.request.urlopen(f"{base_url}/status", timeout=5) as response:
+            status_payload = json.loads(response.read())
         with urllib.request.urlopen(
             f"{base_url}/repositories/railiance-fabric/snapshots",
             timeout=5,
@@ -211,6 +213,8 @@ def test_registry_http_service_serves_queries(tmp_path: Path) -> None:
             library_projection_payload = json.loads(response.read())
         assert providers_payload[0]["provider_id"] == "railiance-platform.openbao.runtime-secrets"
         assert snapshots_payload[0]["commit"] == "test-cli-2"
+        assert status_payload["counts"]["repositories"] == 1
+        assert status_payload["counts"]["snapshots"] == 3
         assert drift_payload["graph"]["removed_nodes"]
         assert artifact_payload["name"] == "OpenBao KV API"
         assert artifacts_payload[0]["artifact_type"] == "openapi"