Refactor payment verification to manual workflow and add comprehensive cleanup tools

Major changes:
• Remove BTCPay Server integration in favor of SilverPAY manual verification
• Add test data cleanup mechanisms (API endpoints and shell scripts)
• Fix compilation errors in TestController (IdentityReference vs CustomerIdentity)
• Add deployment automation scripts for Hostinger VPS
• Enhance integration testing with comprehensive E2E validation
• Add Blazor components and mobile-responsive CSS for admin interface
• Create production environment configuration scripts

Key Features Added:
• Manual payment verification through Admin panel Order Details
• Bulk test data cleanup with proper cascade handling
• Deployment automation with systemd service configuration
• Comprehensive E2E testing suite with SilverPAY integration validation
• Mobile-first admin interface improvements

Security & Production:
• Environment variable configuration for production secrets
• Proper JWT and VAPID key management
• SilverPAY API integration with live credentials
• Database cleanup and maintenance tools

🤖 Generated with Claude Code

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

LittleShop.Tests/Infrastructure/TestWebApplicationFactory.cs

@@ -31,7 +31,6 @@ public class TestWebApplicationFactory : WebApplicationFactory<Program>
 
             // Mock external services that might cause issues in tests
             services.Replace(ServiceDescriptor.Scoped<IPushNotificationService>(_ => Mock.Of<IPushNotificationService>()));
-            services.Replace(ServiceDescriptor.Scoped<IBTCPayServerService>(_ => Mock.Of<IBTCPayServerService>()));
             services.Replace(ServiceDescriptor.Scoped<ITelegramBotManagerService>(_ => Mock.Of<ITelegramBotManagerService>()));
 
             // Build service provider