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/tailwind.config.js

@@ -41,6 +41,23 @@ export default {
           DEFAULT: 'hsl(var(--card))',
           foreground: 'hsl(var(--card-foreground))',
         },
+        success: {
+          DEFAULT: 'hsl(var(--success))',
+          foreground: 'hsl(var(--success-foreground))',
+        },
+        warning: {
+          DEFAULT: 'hsl(var(--warning))',
+          foreground: 'hsl(var(--warning-foreground))',
+        },
+        info: {
+          DEFAULT: 'hsl(var(--info))',
+          foreground: 'hsl(var(--info-foreground))',
+        },
+        surface: {
+          1: 'hsl(var(--surface-1))',
+          2: 'hsl(var(--surface-2))',
+          3: 'hsl(var(--surface-3))',
+        },
       },
       borderRadius: {
         lg: 'var(--radius)',