Separate system operations from core objects in GraphQL endpoints (#12977)

Moves system-level operations (auth, billing, admin) to use the
/metadata endpoint instead of /graphql.

This cleans up the endpoint separation so /graphql is purely for core
objects (Company, People, etc.) and /metadata handles all system
operations.

Part of prep work for webhook/API key core migration.

packages/twenty-front/src/modules/settings/lab/hooks/useLabPublicFeatureFlags.ts

@@ -6,7 +6,7 @@ import { isDefined } from 'twenty-shared/utils';
 import {
   FeatureFlagKey,
   useUpdateLabPublicFeatureFlagMutation,
-} from '~/generated/graphql';
+} from '~/generated-metadata/graphql';
 
 export const useLabPublicFeatureFlags = () => {
   const [error, setError] = useState<string | null>(null);