feat: comprehensive update with Signal, Copilot, themes, and PDF features

## Signal Messaging Integration
- Added SignalService for sending messages to drivers via Signal
- SignalMessage model for tracking message history
- Driver chat modal for real-time messaging
- Send schedule via Signal (ICS + PDF attachments)

## AI Copilot
- Natural language interface for VIP Coordinator
- Capabilities: create VIPs, schedule events, assign drivers
- Help and guidance for users
- Floating copilot button in UI

## Theme System
- Dark/light/system theme support
- Color scheme selection (blue, green, purple, orange, red)
- ThemeContext for global state
- AppearanceMenu in header

## PDF Schedule Export
- VIPSchedulePDF component for schedule generation
- PDF settings (header, footer, branding)
- Preview PDF in browser
- Settings stored in database

## Database Migrations
- add_signal_messages: SignalMessage model
- add_pdf_settings: Settings model for PDF config
- add_reminder_tracking: lastReminderSent for events
- make_driver_phone_optional: phone field nullable

## Event Management
- Event status service for automated updates
- IN_PROGRESS/COMPLETED status tracking
- Reminder tracking for notifications

## UI/UX Improvements
- Driver schedule modal
- Improved My Schedule page
- Better error handling and loading states
- Responsive design improvements

## Other Changes
- AGENT_TEAM.md documentation
- Seed data improvements
- Ability factory updates
- Driver profile page

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/src/app.module.ts

@@ -11,6 +11,10 @@ import { DriversModule } from './drivers/drivers.module';
 import { VehiclesModule } from './vehicles/vehicles.module';
 import { EventsModule } from './events/events.module';
 import { FlightsModule } from './flights/flights.module';
+import { CopilotModule } from './copilot/copilot.module';
+import { SignalModule } from './signal/signal.module';
+import { SettingsModule } from './settings/settings.module';
+import { SeedModule } from './seed/seed.module';
 import { JwtAuthGuard } from './auth/guards/jwt-auth.guard';
 
 @Module({
@@ -32,6 +36,10 @@ import { JwtAuthGuard } from './auth/guards/jwt-auth.guard';
     VehiclesModule,
     EventsModule,
     FlightsModule,
+    CopilotModule,
+    SignalModule,
+    SettingsModule,
+    SeedModule,
   ],
   controllers: [AppController],
   providers: [