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/databases/hooks/useGetDatabaseConnectionTables.ts

@@ -1,7 +1,7 @@
 import { useQuery, WatchQueryFetchPolicy } from '@apollo/client';
 
 import { GET_MANY_REMOTE_TABLES } from '@/databases/graphql/queries/findManyRemoteTables';
-import { useApolloMetadataClient } from '@/object-metadata/hooks/useApolloMetadataClient';
+import { useApolloCoreClient } from '@/object-metadata/hooks/useApolloCoreClient';
 import {
   GetManyRemoteTablesQuery,
   GetManyRemoteTablesQueryVariables,
@@ -20,7 +20,7 @@ export const useGetDatabaseConnectionTables = ({
   shouldFetchPendingSchemaUpdates,
   fetchPolicy,
 }: UseGetDatabaseConnectionTablesParams) => {
-  const apolloMetadataClient = useApolloMetadataClient();
+  const apolloMetadataClient = useApolloCoreClient();
 
   const fetchPolicyOption = fetchPolicy ? { fetchPolicy: fetchPolicy } : {};