♻️ (billing) Refactor billing server code to trpc

apps/builder/src/pages/api/stripe/subscription.ts

@@ -11,6 +11,7 @@ import { getAuthenticatedUser } from '@/features/auth/api'
 import prisma from '@/lib/prisma'
 import { Plan, WorkspaceRole } from 'db'
 
+// TODO: Delete
 const handler = async (req: NextApiRequest, res: NextApiResponse) => {
   const user = await getAuthenticatedUser(req)
   if (!user) return notAuthenticated(res)