refactor(core): adjust graphql hook (#5339)

packages/frontend/graphql/src/index.ts

@@ -3,3 +3,7 @@ export * from './graphql';
 export * from './schema';
 export * from './utils';
 import '@affine/env/global';
+
+import { gqlFetcherFactory } from './fetcher';
+
+export const fetcher = gqlFetcherFactory('/graphql');