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>

supabase/migrations/20250708_add_referral_tracking.sql

@@ -0,0 +1,25 @@
+-- Add referral tracking columns to purchase_attempts table
+ALTER TABLE purchase_attempts 
+ADD COLUMN IF NOT EXISTS referral_source TEXT,
+ADD COLUMN IF NOT EXISTS utm_campaign TEXT,
+ADD COLUMN IF NOT EXISTS utm_medium TEXT,
+ADD COLUMN IF NOT EXISTS utm_source TEXT,
+ADD COLUMN IF NOT EXISTS utm_term TEXT,
+ADD COLUMN IF NOT EXISTS utm_content TEXT,
+ADD COLUMN IF NOT EXISTS referrer_url TEXT,
+ADD COLUMN IF NOT EXISTS landing_page TEXT;
+
+-- Add indexes for better query performance
+CREATE INDEX IF NOT EXISTS idx_purchase_attempts_referral_source ON purchase_attempts(referral_source);
+CREATE INDEX IF NOT EXISTS idx_purchase_attempts_utm_source ON purchase_attempts(utm_source);
+CREATE INDEX IF NOT EXISTS idx_purchase_attempts_utm_campaign ON purchase_attempts(utm_campaign);
+
+-- Add comments to explain the columns
+COMMENT ON COLUMN purchase_attempts.referral_source IS 'High-level referral source (e.g., google, facebook, direct, email)';
+COMMENT ON COLUMN purchase_attempts.utm_campaign IS 'Campaign name from UTM parameters';
+COMMENT ON COLUMN purchase_attempts.utm_medium IS 'Medium from UTM parameters (e.g., email, social, paid)';
+COMMENT ON COLUMN purchase_attempts.utm_source IS 'Source from UTM parameters (e.g., google, facebook, newsletter)';
+COMMENT ON COLUMN purchase_attempts.utm_term IS 'Term from UTM parameters (paid search keywords)';
+COMMENT ON COLUMN purchase_attempts.utm_content IS 'Content from UTM parameters (ad variant)';
+COMMENT ON COLUMN purchase_attempts.referrer_url IS 'Full HTTP referrer URL';
+COMMENT ON COLUMN purchase_attempts.landing_page IS 'Page where user first landed on the site';