refactor(debt): resolve all 10 technical debt items from audit

fix: resolve login 400 — auto-resolve organizationId from email when omitted

chore: stabilization, audit fixes and project synchronization

feat: implement inbound audio/image transcription, secure media proxy, and client-side bulk contact import

chore: remove unused zod import from auth.ts

fix: replace Zod schema with JSON Schema in auth/login to resolve Fastify v5 startup crash

feat: add auth debug logs and trigger fresh deploy

fix: resolve api build errors and multi-tenant unique key constraints

feat: migrate to multi-tenant SaaS architecture with JWT auth and BullMQ notifications