feat: replace email flows with in-app notifications

Add recipient notification detail and filtering, a queued admin composer, and contextual automatic titles. Retire email delivery, obsolete auth routes, newsletter data, and related templates and settings.

.env.example

@@ -31,16 +31,6 @@ REDIS_URL=redis://:change-me@redis:6379/0
 CELERY_BROKER_URL=redis://:change-me@redis:6379/0
 CELERY_RESULT_BACKEND=redis://:change-me@redis:6379/1
 
-# Email
-EMAIL_BACKEND=django.core.mail.backends.smtp.EmailBackend
-EMAIL_HOST=smtp.example.com
-EMAIL_PORT=587
-EMAIL_USE_SSL=False
-EMAIL_USE_TLS=True
-EMAIL_HOST_USER=smtp-user
-EMAIL_HOST_PASSWORD=smtp-password
-DEFAULT_FROM_EMAIL=admin@example.com
-
 # SMS.ir
 SMS_APIKEY=replace-with-sms-ir-api-key
 SMS_AUTH_OTP_TEMPLATE_ID=100000
@@ -67,7 +57,6 @@ CORS_ALLOW_CREDENTIALS=True
 CSRF_COOKIE_SECURE=True
 SESSION_COOKIE_SECURE=True
 FRONTEND_ROOT=https://frontend.example.com
-FRONTEND_PASSWORD_RESET_PAGE=https://frontend.example.com/reset-password
 FRONTEND_CALLBACK_URL=https://frontend.example.com/payments/result
 
 # SSE Notifications