fix(crm): normalize Excel column names before bulk contact upload

fix(clients): resolve file import dialog error and SSE 401

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

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: implement bulk whatsapp campaigns with BullMQ and modular activation refactor (isCrmActive/isEdTechActive)

feat(crm): optimize multimedia pipeline and harden contact schema

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

feat: implement premium animated smart chips in CRM Dashboard chat UI

chore: CRM stabilization sprint completion