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>

frontend/src/hooks/useAuth.ts

@@ -72,6 +72,9 @@ export const useLogin = () => {
       setCookie('access_token', data.access, 7);
       setCookie('refresh_token', data.refresh, 7);
 
+      // Clear any existing masquerade stack - this is a fresh login
+      localStorage.removeItem('masquerade_stack');
+
       // Set user in cache
       queryClient.setQueryData(['currentUser'], data.user);
     },
@@ -91,6 +94,9 @@ export const useLogout = () => {
       deleteCookie('access_token');
       deleteCookie('refresh_token');
 
+      // Clear masquerade stack
+      localStorage.removeItem('masquerade_stack');
+
       // Clear user cache
       queryClient.removeQueries({ queryKey: ['currentUser'] });
       queryClient.clear();