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

chore(web): update branding to Xamlé Studio

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(ui): complete landing page and admin dashboard exports

Initial commit: Monorepo setup with React+Vite, Fastify, Prisma, and Docker Compose