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>

frontend/package.json

@@ -19,6 +19,7 @@
     "@casl/ability": "^6.8.0",
     "@casl/react": "^5.0.1",
     "@heroicons/react": "^2.2.0",
+    "@react-pdf/renderer": "^4.3.2",
     "@tanstack/react-query": "^5.17.19",
     "axios": "^1.6.5",
     "clsx": "^2.1.0",
@@ -26,7 +27,9 @@
     "lucide-react": "^0.309.0",
     "react": "^18.2.0",
     "react-dom": "^18.2.0",
+    "react-hook-form": "^7.71.1",
     "react-hot-toast": "^2.6.0",
+    "react-markdown": "^10.1.0",
     "react-router-dom": "^6.21.3",
     "tailwind-merge": "^2.2.0"
   },