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/test_stripe_concern.rb

@@ -0,0 +1,21 @@
+#!/usr/bin/env ruby
+
+# Create a mock controller to test the StripeConcern
+class TestController
+  include StripeConcern
+  
+  def self.name
+    "TestController"
+  end
+end
+
+# Test the StripeConcern methods
+controller = TestController.new
+
+puts "Testing StripeConcern..."
+puts "stripe_configured? method exists: #{controller.respond_to?(:stripe_configured?)}"
+puts "stripe_configured? result: #{controller.stripe_configured?}"
+
+# Check the Rails configuration directly
+puts "Rails.application.config.stripe: #{Rails.application.config.stripe}"
+puts "Secret key present?: #{Rails.application.config.stripe[:secret_key].present?}"