feat: add Sheet and Sidebar components for improved UI layout

- Introduced a new Sheet component for modal-like functionality with customizable content and animations.
- Implemented a Sidebar component with mobile responsiveness, state management, and keyboard shortcuts for toggling.
- Added Skeleton component for loading states and Tooltip component for enhanced user guidance.
- Created a useIsMobile hook to manage mobile view detection.
- Updated main entry point to render the new PlatformPage component.
- Enhanced styles for sidebar and scrollbar customization in CSS.
- Extended Tailwind configuration to include sidebar color variables for better theming.

frontend/src/main.tsx

@@ -1,8 +1,8 @@
 import React from 'react'
 import { createRoot } from 'react-dom/client'
-import App from './App'
 import { ThemeProvider } from './lib/themeContext'
 import { registerBuiltinNodes } from './lib/registerBuiltinNodes'
+import { PlatformPage } from './app/platform/PlatformPage'
 import './styles.css'
 import '@xyflow/react/dist/style.css'
 
@@ -11,7 +11,7 @@ registerBuiltinNodes()
 createRoot(document.getElementById('root')!).render(
   <React.StrictMode>
     <ThemeProvider>
-      <App />
+      <PlatformPage />
     </ThemeProvider>
   </React.StrictMode>
 )