feat: integrate Cloudflare Turnstile for enhanced security in sign-up and email verification processes. Implement rate limiting for sign-up attempts and add Turnstile validation to prevent abuse. Update environment configuration to support Turnstile keys and enhance user experience with improved error handling and feedback.

feat: add sitemap.xml endpoint and improve SEO metadata across web application. Update landing page and root route with Open Graph and Twitter Card tags, enhance environment configuration for site URL, and introduce robots.txt for better search engine indexing. Include Umami analytics script for tracking user interactions.

feat: add new skills and enhance server configuration. Introduce 'security-review' and 'test-driven-development' skills in skills-lock.json. Update turbo.json to include a test dependency. Create .env.example files for server and web applications to standardize environment variables. Implement security headers in server index.ts for improved security. Enhance ResultSection component to support onClear callback and update generation job handling for better session management. Add encryption for API keys in the backend and implement rate limiting across various routers to prevent abuse.