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/Pages/Shared/MainLayout.razor

@@ -0,0 +1,5 @@
+@inherits LayoutComponentBase
+
+<div class="blazor-container">
+    @Body
+</div>