feat: Implement complete ticket purchasing flow with new TicketsController

- Create new TicketsController with actions for name collection, creation, and checkout
- Add dedicated ticket views (new.html.erb, checkout.html.erb, show.html.erb)
- Update ticket_selection_controller.js to handle form submission via AJAX
- Add store_cart endpoint in EventsController for session-based cart management
- Update routes to support new ticket flow: /tickets/new, /create, /checkout
- Fix attribute name consistency across views (title→name, starts_at→start_time)
- Add Stripe checkout integration with proper error handling
- Remove deprecated collect_names flow in favor of streamlined approach

The flow is now: Event selection → AJAX cart storage → Name collection → Checkout → Payment

bin/debug_stripe_config.rb

@@ -0,0 +1,19 @@
+#!/usr/bin/env ruby
+
+# Test script to verify Stripe configuration in controller context
+puts "Testing Stripe configuration..."
+puts "Rails.application.config.stripe:"
+puts Rails.application.config.stripe.inspect
+
+puts "\nChecking secret_key:"
+secret_key = Rails.application.config.stripe[:secret_key]
+puts "Secret key present: #{secret_key.present?}"
+puts "Secret key length: #{secret_key.length if secret_key.present?}"
+
+puts "\nChecking publishable_key:"
+publishable_key = Rails.application.config.stripe[:publishable_key]
+puts "Publishable key present: #{publishable_key.present?}"
+
+puts "\nChecking signing_secret:"
+signing_secret = Rails.application.config.stripe[:signing_secret]
+puts "Signing secret present: #{signing_secret.present?}"