add theme

src/main.tsx

@@ -1,11 +1,14 @@
 import React from 'react'
 import { createRoot } from 'react-dom/client'
 import App from './App'
+import { ThemeProvider } from './lib/themeContext'
 import './styles.css'
-import 'reactflow/dist/style.css'
+import '@xyflow/react/dist/style.css'
 
 createRoot(document.getElementById('root')!).render(
   <React.StrictMode>
-    <App />
+    <ThemeProvider>
+      <App />
+    </ThemeProvider>
   </React.StrictMode>
 )