Recap

To recap, we have added a new feature to the application, which is replying to posts.

1. We updated the Prisma schema to add new parent and replies relations to the Post model.
2. We ran the migration to update the database.
3. A tRPC thread subrouter was created for this feature, and the new router was added to the application router.
4. The reply mutation procedure was added to the thread subrouter, and the procedure's input was validated using zod.
5. The new procedure can automatically be used in the client application using the trpc.thread.reply.useMutation() hook that was automatically exposed by tRPC.
6. The input data can be validated using zod and react-hook-form before the mutation was called.