feat: implement RAG dashboard with MUI and react-router

Add new RAG dashboard feature including:
- Main application layout with header and sidebar
- Multiple pages (Home, KnowledgeBase, PipelineConfig, Dashboard, MCP)
- Theme configuration and styling
- Routing setup with protected routes
- Login page and authentication flow
- Various UI components and mock data for dashboard views

src/App.tsx

@@ -1,35 +1,17 @@
-import { useState } from 'react'
-import reactLogo from './assets/react.svg'
-import viteLogo from '/vite.svg'
-import './App.css'
+import { BrowserRouter } from 'react-router-dom';
+import { CssBaseline, ThemeProvider } from '@mui/material';
+import { theme } from './theme';
+import AppRoutes from './routes';
 
 function App() {
-  const [count, setCount] = useState(0)
-
   return (
-    <>
-      <div>
-        <a href="https://vite.dev" target="_blank">
-          <img src={viteLogo} className="logo" alt="Vite logo" />
-        </a>
-        <a href="https://react.dev" target="_blank">
-          <img src={reactLogo} className="logo react" alt="React logo" />
-        </a>
-      </div>
-      <h1>Vite + React</h1>
-      <div className="card">
-        <button onClick={() => setCount((count) => count + 1)}>
-          count is {count}
-        </button>
-        <p>
-          Edit <code>src/App.tsx</code> and save to test HMR
-        </p>
-      </div>
-      <p className="read-the-docs">
-        Click on the Vite and React logos to learn more
-      </p>
-    </>
-  )
+    <ThemeProvider theme={theme}>
+      <CssBaseline />
+      <BrowserRouter>
+        <AppRoutes />
+      </BrowserRouter>
+    </ThemeProvider>
+  );
 }
 
-export default App
+export default App;