feat: Merge PDF ticket generation functionality from feat/pdf-ticket branch

- Add TicketPdfGenerator service for creating PDF tickets with QR codes
- Implement download_ticket action in TicketsController
- Update ticket routes to support both ID and QR code access
- Add to_pdf method to Ticket model using TicketPdfGenerator
- Resolve conflicts between email notifications and PDF ticket features
- Maintain backward compatibility with existing QR code routes

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

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

config/routes.rb

@@ -38,9 +38,9 @@ Rails.application.routes.draw do
   get "events",                      to: "events#index",           as: "events"
   get "events/:slug.:id",            to: "events#show",            as: "event"
 
-  # === Orders ===
-  get "events/:slug.:id/orders/new", to: "orders#new", as: "event_order_new"
-  post "events/:slug.:id/orders", to: "orders#create", as: "event_order_create"
+  # === Orders (scoped to events) ===
+  get "orders/new/events/:slug.:id", to: "orders#new", as: "event_order_new"
+  post "orders/create/events/:slug.:id", to: "orders#create", as: "event_order_create"
 
   resources :orders, only: [ :show ] do
     member do
@@ -50,18 +50,20 @@ Rails.application.routes.draw do
     end
   end
 
-  get   "orders/payments/success",      to: "orders#payment_success", as: "order_payment_success"
-  get   "orders/payments/cancel",       to: "orders#payment_cancel",  as: "order_payment_cancel"
+  get   "orders/payments/success", to: "orders#payment_success",  as: "order_payment_success"
+  get   "orders/payments/cancel",  to: "orders#payment_cancel",   as: "order_payment_cancel"
 
-  # Legacy ticket routes - redirect to order system
+  # Legacy routes - redirect to order system  
   get   "events/:slug.:id/tickets/checkout", to: "tickets#checkout", as: "ticket_checkout"
   post  "events/:slug.:id/tickets/retry",    to: "tickets#retry_payment", as: "ticket_retry_payment"
   get   "payments/success", to: "tickets#payment_success", as: "payment_success"
   get   "payments/cancel",  to: "tickets#payment_cancel", as: "payment_cancel"
 
   # === Tickets ===
-  get   "tickets/:qr_code", to: "tickets#show", as: "ticket"
-  get   "tickets/:qr_code/download", to: "events#download_ticket", as: "ticket_download"
+  # Support both ticket_id and qr_code for backward compatibility
+  get   "tickets/:qr_code", to: "tickets#show", as: "ticket", constraints: { qr_code: /[^\/]+/ }
+  get   "tickets/:ticket_id", to: "tickets#show", as: "ticket_by_id"
+  get   "tickets/:ticket_id/download", to: "tickets#download_ticket", as: "download_ticket"
 
   # === Promoter Routes ===
   namespace :promoter do