feat: enhance studio app with left panel toggle and loading state

- Added a left panel toggle button in the header to show/hide the ViewList component.
- Integrated loading state management in the studio store for better user feedback during data fetching.
- Updated the ViewList component to utilize a dropdown menu for editing and deleting views.
- Improved UI elements with consistent border styles and loading indicators.
- Refactored the DataItemForm and ViewFormItem components for better user experience and added clipboard copy functionality.
- Introduced a new DropdownMenu component for better dropdown handling across the application.

web/package.json

@@ -30,6 +30,7 @@
     "@kevisual/registry": "^0.0.1",
     "@kevisual/router": "^0.0.52",
     "@radix-ui/react-checkbox": "^1.3.3",
+    "@radix-ui/react-dropdown-menu": "^2.1.16",
     "@radix-ui/react-label": "^2.1.8",
     "@radix-ui/react-slot": "^1.2.4",
     "@tailwindcss/vite": "^4.1.18",