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>

frontend/src/api/auth.ts

@@ -20,9 +20,10 @@ export interface MasqueradeStackEntry {
 }
 
 export interface LoginResponse {
-  access: string;
-  refresh: string;
-  user: {
+  // Regular login success
+  access?: string;
+  refresh?: string;
+  user?: {
     id: number;
     username: string;
     email: string;
@@ -37,6 +38,11 @@ export interface LoginResponse {
     business_subdomain?: string;
   };
   masquerade_stack?: MasqueradeStackEntry[];
+  // MFA challenge response
+  mfa_required?: boolean;
+  user_id?: number;
+  mfa_methods?: ('SMS' | 'TOTP' | 'BACKUP')[];
+  phone_last_4?: string;
 }
 
 export interface User {