chore: execute Sprint 38 technical debt resolution (Type Safety, Zod validation, Vitest, Mock LLM extracted)

feat: Genspark-Standard upgrade, MLOps audit fixes, and XAMLÉ branding

feat(admin): build Ground Truth Training Lab to calculate WER and capture dictionary improvements

feat(api): add whisper confidence calibration script and endpoint

fix(api): remove redundant /admin prefix in admin routes to fix dashboard 404

feat(admin): add viewing full chat history in user list

feat(admin): human-in-the-loop dashboard base, add PENDING_REVIEW logic and audio overdrive worker

feat(prod): implementation of missing features for production readiness

fix(security): audit fixes — Stripe webhook scope, fail-fast secrets, prisma singleton, worker auth, Zod validation, WA number env var

feat: implement dynamic admin dashboard with API data