Major Enhancement: NestJS Migration + CASL Authorization + Error Handling

Complete rewrite from Express to NestJS with enterprise-grade features:

## Backend Improvements
- Migrated from Express to NestJS 11.0.1 with TypeScript
- Implemented Prisma ORM 7.3.0 for type-safe database access
- Added CASL authorization system replacing role-based guards
- Created global exception filters with structured logging
- Implemented Auth0 JWT authentication with Passport.js
- Added vehicle management with conflict detection
- Enhanced event scheduling with driver/vehicle assignment
- Comprehensive error handling and logging

## Frontend Improvements
- Upgraded to React 19.2.0 with Vite 7.2.4
- Implemented CASL-based permission system
- Added AbilityContext for declarative permissions
- Created ErrorHandler utility for consistent error messages
- Enhanced API client with request/response logging
- Added War Room (Command Center) dashboard
- Created VIP Schedule view with complete itineraries
- Implemented Vehicle Management UI
- Added mock data generators for testing (288 events across 20 VIPs)

## New Features
- Vehicle fleet management (types, capacity, status tracking)
- Complete 3-day Jamboree schedule generation
- Individual VIP schedule pages with PDF export (planned)
- Real-time War Room dashboard with auto-refresh
- Permission-based navigation filtering
- First user auto-approval as administrator

## Documentation
- Created CASL_AUTHORIZATION.md (comprehensive guide)
- Created ERROR_HANDLING.md (error handling patterns)
- Updated CLAUDE.md with new architecture
- Added migration guides and best practices

## Technical Debt Resolved
- Removed custom authentication in favor of Auth0
- Replaced role checks with CASL abilities
- Standardized error responses across API
- Implemented proper TypeScript typing
- Added comprehensive logging

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

frontend/src/lib/utils.ts

@@ -0,0 +1,34 @@
+import { type ClassValue, clsx } from 'clsx';
+import { twMerge } from 'tailwind-merge';
+
+export function cn(...inputs: ClassValue[]) {
+  return twMerge(clsx(inputs));
+}
+
+export function formatDate(date: string | Date): string {
+  const d = typeof date === 'string' ? new Date(date) : date;
+  return d.toLocaleDateString('en-US', {
+    year: 'numeric',
+    month: 'short',
+    day: 'numeric',
+  });
+}
+
+export function formatDateTime(date: string | Date): string {
+  const d = typeof date === 'string' ? new Date(date) : date;
+  return d.toLocaleString('en-US', {
+    year: 'numeric',
+    month: 'short',
+    day: 'numeric',
+    hour: '2-digit',
+    minute: '2-digit',
+  });
+}
+
+export function formatTime(date: string | Date): string {
+  const d = typeof date === 'string' ? new Date(date) : date;
+  return d.toLocaleTimeString('en-US', {
+    hour: '2-digit',
+    minute: '2-digit',
+  });
+}