✅ Supabase Row-Level Security on all 12 tables

✅ Content Security Policy headers configured

✅ CSRF protection on all mutations

✅ Rate limiting on API endpoints

✅ Input validation with Zod schemas

✅ OAuth 2.0 for Gmail & Slack

✅ JWT token rotation & refresh

✅ Org-scoped database queries

✅ XSS prevention in email rendering

✅ Secure WebSocket connections