feat: integrate Radix UI toggle components and replace custom toast implementation with Sonner

- Added @radix-ui/react-toggle and @radix-ui/react-toggle-group to package dependencies.
- Implemented ToggleGroup and Toggle components for improved UI interaction.
- Replaced custom toast notifications with Sonner for better user feedback.
- Updated CanvasPage and ProjectsPage to utilize new toast notifications.
- Removed obsolete toast context and provider.
- Enhanced ProjectsPage with a toggle view for project display (cards/table).

frontend/src/main.tsx

@@ -1,8 +1,8 @@
 import React from 'react'
 import { createRoot } from 'react-dom/client'
 import { BrowserRouter, Navigate, Route, Routes } from 'react-router-dom'
+import { Toaster } from 'sonner'
 import { ThemeProvider } from './lib/themeContext'
-import { ToastProvider } from './components/ui/toast'
 import { registerBuiltinNodes } from './lib/registerBuiltinNodes'
 import { PlatformPage } from './app/platform/PlatformPage'
 import { ProjectsPage } from './app/platform/ProjectsPage'
@@ -15,17 +15,16 @@ registerBuiltinNodes()
 createRoot(document.getElementById('root')!).render(
   <React.StrictMode>
     <ThemeProvider>
-      <ToastProvider>
-        <BrowserRouter>
-          <Routes>
-            <Route path="/" element={<PlatformPage />}>
-              <Route index element={<Navigate to="/projects" replace />} />
-              <Route path="projects" element={<ProjectsPage />} />
-              <Route path="projects/:projectId" element={<CanvasRoute />} />
-            </Route>
-          </Routes>
-        </BrowserRouter>
-      </ToastProvider>
+      <BrowserRouter>
+        <Routes>
+          <Route path="/" element={<PlatformPage />}>
+            <Route index element={<Navigate to="/projects" replace />} />
+            <Route path="projects" element={<ProjectsPage />} />
+            <Route path="projects/:projectId" element={<CanvasRoute />} />
+          </Route>
+        </Routes>
+      </BrowserRouter>
+      <Toaster richColors position="bottom-right" />
     </ThemeProvider>
   </React.StrictMode>
 )