fix(prompts): enforce language isolation in all AI prompts

fix(bot): eliminate double feedback, fix gemini model, fix multilingual prompts

feat: backlog P0→P3 — toast system, payments, tenant isolation, feedback handler, i18n parity

feat: implement whatsapp templates management with security hardening, audit logs, and crm integration

feat: push notifications, CRM analytics, Fastify v5 upgrades, schema updates

feat: B2B SaaS Multi-tenant architecture & Tech Debt Resolution

Refactor: Isolated AI prompts into @repo /prompts package for better maintainability