Question: Is the null return type necessary in usePreloadedAuthQuery?

Hi!

The [documentation](https://labs.convex.dev/better-auth/migrations/migrate-to-0-10#nextjs-changes) states that the `usePreloadedAuthQuery` function is a drop-in replacement for `usePreloadedQuery`. However, the return signature of `usePreloadedAuthQuery` is following:

https://github.com/get-convex/better-auth/blob/5751ea8ae9952c4803d8ca3f3deea96942dd98d0/src/nextjs/client.tsx#L44

while the `usePreloadedQuery` doesn't have the added `null` return:

https://github.com/get-convex/convex-backend/blob/fcef824ddb49c81f92803d01e8859dd2fad4b7b9/npm-packages/convex/src/react/hydration.tsx#L35

Is this intentional?

Compare the return signature in src/nextjs/client.tsx at line 44 with the referenced usePreloadedQuery definition in Convex's react/hydration.tsx. Check the migration documentation, then determine whether the nullable return is intentional; done means the behavior and type contract are clarified and any necessary documentation or type update is covered.

Written by the indexing model from the issue text.