feat: Add SMTP settings and collapsible email configuration UI

- Add SMTP fields to TicketEmailSettings model (host, port, TLS/SSL, credentials, from email/name)
- Update serializers with SMTP fields and is_smtp_configured flag
- Add TicketEmailTestSmtpView for testing SMTP connections
- Update frontend API types and hooks for SMTP settings
- Add collapsible IMAP and SMTP configuration sections with "Configured" badges
- Fix TypeScript errors in mockData.ts (missing required fields, type mismatches)

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

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

smoothschedule/config/settings/multitenancy.py

@@ -43,6 +43,7 @@ SHARED_APPS = [
     'crispy_forms',
     'crispy_bootstrap5',
     'csp',
+    'djstripe',  # Stripe integration
     'tickets', # Ticket system - shared for platform support access
     'smoothschedule.public_api', # Public API v1 for third-party integrations
 ]