feat: Modularize event management system - 98.7% reduction in main file size

BREAKING CHANGES:
- Refactored monolithic manage.astro (7,623 lines) into modular architecture
- Original file backed up as manage-old.astro

NEW ARCHITECTURE:
✅ 5 Utility Libraries:
  - event-management.ts: Event data operations & formatting
  - ticket-management.ts: Ticket CRUD operations & sales data
  - seating-management.ts: Seating map management & layout generation
  - sales-analytics.ts: Sales metrics, reporting & data export
  - marketing-kit.ts: Marketing asset generation & social media

✅ 5 Shared Components:
  - TicketTypeModal.tsx: Reusable ticket type creation/editing
  - SeatingMapModal.tsx: Advanced seating map editor with drag-and-drop
  - EmbedCodeModal.tsx: Widget embedding with customization
  - OrdersTable.tsx: Comprehensive orders table with sorting/pagination
  - AttendeesTable.tsx: Attendee management with export capabilities

✅ 11 Tab Components:
  - TicketsTab.tsx: Ticket management with card/list views
  - VenueTab.tsx: Seating map management & venue configuration
  - OrdersTab.tsx: Sales data & order management
  - AttendeesTab.tsx: Attendee check-in & management
  - PresaleTab.tsx: Presale code generation & tracking
  - DiscountTab.tsx: Discount code management
  - AddonsTab.tsx: Add-on product management
  - PrintedTab.tsx: Printed ticket barcode management
  - SettingsTab.tsx: Event configuration & custom fields
  - MarketingTab.tsx: Marketing kit with social media templates
  - PromotionsTab.tsx: Campaign & promotion management

✅ 4 Infrastructure Components:
  - TabNavigation.tsx: Responsive tab navigation system
  - EventManagement.tsx: Main orchestration component
  - EventHeader.astro: Event information header
  - QuickStats.astro: Statistics dashboard

BENEFITS:
- 98.7% reduction in main file size (7,623 → ~100 lines)
- Dramatic improvement in maintainability and team collaboration
- Component-level testing now possible
- Reusable components across multiple features
- Lazy loading support for better performance
- Full TypeScript support with proper interfaces
- Separation of concerns: business logic separated from UI

🤖 Generated with [Claude Code](https://claude.ai/code)

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

src/pages/e/[slug].astro

@@ -63,6 +63,17 @@ const formattedTime = eventDate.toLocaleTimeString('en-US', {
   <div class="min-h-screen bg-gradient-to-br from-slate-50 via-white to-slate-100">
     <main class="max-w-5xl mx-auto py-6 px-4 sm:px-6 lg:px-8">
       <div class="bg-white shadow-2xl rounded-2xl overflow-hidden border border-slate-200">
+        <!-- Event Image -->
+        {event.image_url && (
+          <div class="w-full h-64 md:h-72 lg:h-80 overflow-hidden">
+            <img 
+              src={event.image_url} 
+              alt={event.title}
+              class="w-full h-full object-cover"
+            />
+          </div>
+        )}
+        
         <div class="px-6 py-6">
           <!-- Compact Header -->
           <div class="bg-gradient-to-r from-slate-800 to-slate-900 rounded-xl p-6 mb-6 text-white">