fix: Add missing Switch UI component for ToggleField

- Installed @radix-ui/react-switch
- Created switch.tsx following existing UI component patterns
- Fixes import error in ToggleField component
- Dev server now running successfully

admin-spa/package.json

@@ -21,6 +21,7 @@
         "@radix-ui/react-select": "^2.2.6",
         "@radix-ui/react-separator": "^1.1.7",
         "@radix-ui/react-slot": "^1.2.3",
+        "@radix-ui/react-switch": "^1.2.6",
         "@radix-ui/react-tabs": "^1.1.13",
         "@tanstack/react-query": "^5.90.5",
         "class-variance-authority": "^0.7.1",