feat: implement header/footer visibility controls for checkout and thankyou pages

- Created LayoutWrapper component to conditionally render header/footer based on route
- Created MinimalHeader component (logo only)
- Created MinimalFooter component (trust badges + policy links)
- Created usePageVisibility hook to get visibility settings per page
- Wrapped ClassicLayout with LayoutWrapper for conditional rendering
- Header/footer visibility now controlled directly in React SPA
- Settings: show/minimal/hide for both header and footer
- Background color support for checkout and thankyou pages

admin-spa/package.json

@@ -29,6 +29,7 @@
         "@radix-ui/react-radio-group": "^1.3.8",
         "@radix-ui/react-select": "^2.2.6",
         "@radix-ui/react-separator": "^1.1.7",
+        "@radix-ui/react-slider": "^1.3.6",
         "@radix-ui/react-slot": "^1.2.3",
         "@radix-ui/react-switch": "^1.2.6",
         "@radix-ui/react-tabs": "^1.1.13",