Supabase Firebase Auth third-party guide code example uses nonexistent `.id` instead of `.uid`
The Supabase documentation example for assigning role custom claims with Firebase Admin SDK incorrectly references `userRecord.id`, which does not exist on Firebase UserRecord objects. The correct property is `userRecord.uid`. Following the example as written causes a runtime error when calling `setCustomUserClaims` with `undefined` as the user identifier.
