feat: production launch — email audit, team invites, security headers, router fixes

- Fix loyalty & monitoring router bugs (_get_router → named routers)
- Implement team invitation email with send_template + seed templates (en/fr/de)
- Add SecurityHeadersMiddleware (nosniff, HSTS, referrer-policy, permissions-policy)
- Build email audit admin page: service, schemas, API, page route, menu, i18n, HTML, JS
- Clean stale TODO in platform-menu-config.js
- Add 67 tests (unit + integration) covering all new functionality

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/modules/messaging/routes/api/admin.py

@@ -13,7 +13,7 @@ from fastapi import APIRouter, Depends
 from app.api.deps import require_module_access
 from app.modules.enums import FrontendType
 
-from .admin_email_templates import admin_email_templates_router
+from .admin_email_templates import admin_email_logs_router, admin_email_templates_router
 from .admin_messages import admin_messages_router
 from .admin_notifications import admin_notifications_router
 
@@ -25,3 +25,4 @@ router = APIRouter(
 router.include_router(admin_messages_router, tags=["admin-messages"])
 router.include_router(admin_notifications_router, tags=["admin-notifications"])
 router.include_router(admin_email_templates_router, tags=["admin-email-templates"])
+router.include_router(admin_email_logs_router, tags=["admin-email-logs"])