Sass Ninja Kit Cursor Rules

# Cursor rules — sass-ninja-kit

This repo is a reusable multi-tenant SaaS boilerplate template (infrastructure,
not a single product). Honor these rules for every change:

1. Config-driven: every optional feature is gated by a flag in
   `config/features.ts`, resolved from env vars. Never hardcode an optional
   feature as always-on.
2. Adapter pattern: anything swappable (database, storage, email, AI providers)
   sits behind one interface with one or more concrete implementations. App code
   imports the interface only, never a concrete adapter directly.
3. Multi-tenant by default: every tenant-scoped table has `organization_id`.
   Single-tenant projects get one silent default org per user — no extra UI.
4. Table triad rule: every new table/model ships with a Zod schema, a seed-data
   entry, and an adapter method — in the same commit.
5. Stay in scope: don't add features, routes, or UI beyond the current phase.
   Note gaps with a `// Deferred to later phase` comment instead of building.
6. Prefer editing/extending existing files over regenerating whole files.

Stack: Next.js 15 (App Router) + TypeScript + TailwindCSS + shadcn/ui on Vercel.
See `docs/architecture/overview.md`.