security(files): scrub connector credentials on deletion

tests/test_connector_deployment.py

@@ -81,6 +81,37 @@ class ConnectorDeploymentBoundaryTests(unittest.TestCase):
             )
         session.get.assert_not_called()
 
+    def test_api_profiles_cannot_create_unowned_external_secret_references(self) -> None:
+        with self.assertRaisesRegex(ConnectorDeploymentConfigurationError, "provider ownership"):
+            reject_api_controlled_deployment_references(secret_ref="vault:tenant-1:files")
+
+        session = MagicMock()
+        with self.assertRaisesRegex(ConnectorDeploymentConfigurationError, "provider ownership"):
+            create_connector_profile_row(
+                session,
+                tenant_id="tenant-1",
+                user_id="user-1",
+                profile_id="unsafe-secret-ref",
+                label="Unsafe secret reference",
+                provider="webdav",
+                scope_type="tenant",
+                credential_mode="secret_ref",
+                secret_ref="vault:tenant-1:files",
+            )
+        session.get.assert_not_called()
+
+    def test_api_profiles_cannot_hide_plaintext_credentials_in_metadata(self) -> None:
+        for metadata in (
+            {"secret_access_key": "plaintext-secret"},
+            {"credentials": {"password": "plaintext-secret"}},
+            {"provider": {"refresh_token": "plaintext-secret"}},
+        ):
+            with self.subTest(metadata=metadata), self.assertRaisesRegex(
+                ConnectorDeploymentConfigurationError,
+                "dedicated encrypted credential fields",
+            ):
+                reject_api_controlled_deployment_references(metadata=metadata)
+
     def test_profile_responses_hide_environment_and_local_ca_references(self) -> None:
         profile = ConnectorProfile(
             id="deployment-s3",