feat: Email templates, bulk delete, communication credits, plan features

- Add email template presets for Browse Templates tab (12 templates)
- Add bulk selection and deletion for My Templates tab
- Add communication credits system with Twilio integration
- Add payment views for credit purchases and auto-reload
- Add SMS reminder and masked calling plan permissions
- Fix appointment status mapping (frontend/backend mismatch)
- Clear masquerade stack on login/logout for session hygiene
- Update platform settings with credit configuration
- Add new migrations for Twilio and Stripe payment fields

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

smoothschedule/config/settings/multitenancy.py

@@ -48,6 +48,7 @@ SHARED_APPS = [
     'tickets', # Ticket system - shared for platform support access
     'notifications', # Notification system - shared for platform to notify tenants
     'smoothschedule.public_api', # Public API v1 for third-party integrations
+    'smoothschedule.comms_credits', # Communication credits (SMS/calling) - shared for billing
 ]
 
 # Tenant-specific apps - Each tenant gets isolated data in their own schema
@@ -55,7 +56,6 @@ TENANT_APPS = [
     'django.contrib.contenttypes',  # Needed for tenant schemas
     'schedule',  # Resource scheduling with configurable concurrency
     'payments',  # Stripe Connect payments bridge
-    'communication',  # Twilio masked communications
     # Add your tenant-scoped business logic apps here:
     # 'appointments',
     # 'customers',