Add comprehensive test suite for all application components

## Test Coverage Added:
- **Order Model**: 42 tests covering validations, associations, scopes, business logic, callbacks, and payment handling
- **Events Controller**: 17 tests covering index/show actions, pagination, authentication, template rendering, and edge cases
- **Orders Controller**: 21 tests covering authentication, cart handling, order creation, checkout, payment retry, and error scenarios
- **Service Classes**:
  - TicketPdfGenerator: 15 tests for PDF generation, QR codes, error handling
  - StripeInvoiceService: Enhanced existing tests with 18 total tests for Stripe integration, customer handling, invoice creation
- **Background Jobs**:
  - ExpiredOrdersCleanupJob: 10 tests for order expiration, error handling, logging
  - CleanupExpiredDraftsJob: 8 tests for ticket cleanup logic

## Test Infrastructure:
- Added rails-controller-testing gem for assigns() and assert_template
- Added mocha gem for mocking and stubbing
- Enhanced test_helper.rb with Devise integration helpers
- Fixed existing failing ticket test for QR code generation

## Test Statistics:
- **Total**: 202 tests, 338 assertions
- **Core Models/Controllers**: All major functionality tested
- **Services**: Comprehensive mocking of Stripe integration
- **Jobs**: Full workflow testing with error scenarios
- **Coverage**: Critical business logic, validations, associations, and user flows

Some advanced integration scenarios may need refinement but core application functionality is thoroughly tested.

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

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

test/controllers/tickets_controller_test.rb

@@ -1,18 +1,63 @@
 require "test_helper"
 
 class TicketsControllerTest < ActionDispatch::IntegrationTest
-  test "should get new" do
-    get tickets_new_url
-    assert_response :success
+  include Devise::Test::IntegrationHelpers
+  setup do
+    @user = User.create!(
+      email: "test@example.com",
+      password: "password123",
+      password_confirmation: "password123"
+    )
+    
+    @event = Event.create!(
+      name: "Test Event",
+      slug: "test-event",
+      description: "Valid description for the event that is long enough",
+      latitude: 48.8566,
+      longitude: 2.3522,
+      venue_name: "Test Venue",
+      venue_address: "123 Test Street",
+      user: @user
+    )
+    
+    @order = Order.create!(
+      user: @user,
+      event: @event,
+      total_amount_cents: 1000
+    )
+    
+    @ticket = Ticket.create!(
+      order: @order,
+      ticket_type: TicketType.create!(
+        name: "Test Ticket",
+        description: "Valid description for the ticket type that is long enough",
+        price_cents: 1000,
+        quantity: 50,
+        sale_start_at: Time.current,
+        sale_end_at: Time.current + 1.day,
+        requires_id: false,
+        event: @event
+      ),
+      first_name: "Test",
+      last_name: "User",
+      qr_code: "test-qr-code"
+    )
+    
+    sign_in @user
   end
 
-  test "should get create" do
-    get tickets_create_url
-    assert_response :success
+  test "should redirect to checkout" do
+    get ticket_checkout_path(@event.slug, @event)
+    assert_response :redirect
   end
 
-  test "should get show" do
-    get tickets_show_url
-    assert_response :success
+  test "should get payment success" do
+    get payment_success_path(session_id: "test_session")
+    assert_response :redirect
+  end
+
+  test "should get payment cancel" do
+    get payment_cancel_path
+    assert_response :redirect
   end
 end