feat: add more synonyms for кримбр

feat: tune Whisper settings and add word mappings

security: sync CORS and error handling security updates in main repo

feat: implement caching, rate limiter, and security headers (CSP) for decoupled deploy

chore: handle missing client dist path gracefully in server

chore: disable EventSub listener in server

feat: prepare transition to decoupled hosting (Render + Netlify + Supabase)