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/pyproject.toml

@@ -195,5 +195,7 @@ dependencies = [
     "sentry-sdk==2.46.0",
     "whitenoise==6.11.0",
     "stripe>=7.0.0",
+    "dj-stripe>=2.9.0",
     "django-csp==3.8.0",
+    "twilio>=9.0.0",
 ]