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/useUpdateOneDatabaseConnection.ts

@@ -1,7 +1,7 @@
 import { useMutation } from '@apollo/client';
 
 import { UPDATE_ONE_DATABASE_CONNECTION } from '@/databases/graphql/mutations/updateOneDatabaseConnection';
-import { useApolloMetadataClient } from '@/object-metadata/hooks/useApolloMetadataClient';
+import { useApolloCoreClient } from '@/object-metadata/hooks/useApolloCoreClient';
 import {
   UpdateRemoteServerInput,
   UpdateServerMutation,
@@ -9,7 +9,7 @@ import {
 } from '~/generated-metadata/graphql';
 
 export const useUpdateOneDatabaseConnection = () => {
-  const apolloMetadataClient = useApolloMetadataClient();
+  const apolloMetadataClient = useApolloCoreClient();
 
   const [mutate] = useMutation<
     UpdateServerMutation,