- Webhook HMAC: added consumer verification JSDoc with Node.js example using crypto.timingSafeEqual - CSRF rate limiting: 20 requests/15min per IP on NextAuth /csrf endpoint - Renamed withRateLimit to withPostRateLimit/withGetRateLimit for clarity - 429 responses include Retry-After header Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>