Next.js SaaS .cursorrules Template

Create a .cursorrules file in the project root with the following rules for a Next.js SaaS application:

PROJECT STACK:
- Next.js 14+ with App Router (NO pages/ directory)
- TypeScript strict mode — no 'any' types
- Tailwind CSS for styling — no CSS modules, no styled-components
- Supabase for auth, database, and storage
- Stripe for payments
- Resend for transactional emails

FILE CONVENTIONS:
- Components: src/components/[feature]/ComponentName.tsx (PascalCase)
- Pages: src/app/[route]/page.tsx
- API routes: src/app/api/[route]/route.ts
- Server actions: src/app/actions/[name].ts with 'use server'
- Types: src/types/[name].ts
- Utils: src/lib/[name].ts
- Supabase client: src/lib/supabase/client.ts (browser) and server.ts (server)

CODING RULES:
- Default to Server Components. Only add 'use client' when using hooks, event handlers, or browser APIs.
- Use next/image for all images. Never use <img> tags.
- Use next/link for all navigation. Never use <a> tags for internal links.
- Fetch data in Server Components using Supabase server client.
- Handle mutations with Server Actions or API routes, never client-side Supabase writes.
- All forms must have loading states, error handling, and success feedback.
- Use Zod for validation on both client and server.

DO NOT:
- Use pages/ directory or getServerSideProps/getStaticProps
- Install ORMs (Prisma, Drizzle) — use Supabase client directly
- Use CSS-in-JS libraries
- Create barrel exports (index.ts re-exports)
- Use default exports except for page.tsx and layout.tsx

ENVIRONMENT VARIABLES:
- NEXT_PUBLIC_SUPABASE_URL, NEXT_PUBLIC_SUPABASE_ANON_KEY
- SUPABASE_SERVICE_ROLE_KEY (server only)
- STRIPE_SECRET_KEY, STRIPE_WEBHOOK_SECRET
- RESEND_API_KEY
- NEXT_PUBLIC_SITE_URL