feat: add React FieldRenderer system for settings and metaboxes

Complete React-based field rendering system that replaces WPCFTO Vue.js
layer while maintaining PHP field configuration compatibility.

Components:
- FieldRenderer: Main renderer with tabs support (metabox) and direct mode (settings)
- FieldTypes: 15+ field types (Text, Number, Select, Radio, Date, etc.)
- RepeaterField: Collapsible repeater with currency label parsing
- DependencyEngine: Show/hide fields based on conditions
- ValidationEngine: Client-side validation with error messages
- SettingsRenderer: Settings page with AJAX save to wp_options

Features:
- Repeater rows collapsed by default with readable currency titles
- Searchable dropdowns using Popover + Command pattern
- Proper label resolution for pre-selected values
- Hidden input sync for WordPress form submission

Also includes:
- FieldConfigBridge: Transform PHP configs to React format
- Updated Settings.php for React-based settings page
- Radio-group UI component
- wp-admin-restore.css for admin panel isolation

package.json

@@ -27,6 +27,7 @@
     "@radix-ui/react-dropdown-menu": "^2.1.16",
     "@radix-ui/react-label": "^2.1.8",
     "@radix-ui/react-popover": "^1.1.15",
+    "@radix-ui/react-radio-group": "^1.3.8",
     "@radix-ui/react-select": "^2.2.6",
     "@radix-ui/react-separator": "^1.1.8",
     "@radix-ui/react-switch": "^1.2.6",
@@ -40,6 +41,8 @@
     "@wordpress/icons": "^9.0.0",
     "class-variance-authority": "^0.7.1",
     "clsx": "^2.1.1",
+    "cmdk": "^1.1.1",
+    "radix-ui": "^1.4.3",
     "sonner": "^2.0.7",
     "tailwind-merge": "^3.5.0",
     "tailwindcss": "^4.2.2"