Adds a shared requireAuthenticated tRPC middleware (reads the server- resolved ctx.user from createTrpcContext) and applies it to every mutating feature procedure — blog.createArticle and media.deleteMedia were anonymous-callable (audit finding B7). Read-only queries stay public; features compose <x>ProtectedProcedure from their error-mapped base procedure. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>