The top-level dev/build/start scripts now run scripts/dispatch.js, which
loads .env.local via node --env-file-if-exists and execs either the
:next or :tanstack variant based on STUDIO_FRAMEWORK. Locally the env
var lives in apps/studio/.env.local (gitignored) so the developer's
machine opts into TanStack; Vercel's Next.js prod project leaves it
unset and gets the next path. Adds :tanstack variants alongside the
existing :next ones for explicit selection.
