feat: initialize React frontend with minimalistic Matrix theme

decnet_web/src/App.tsx

@@ -0,0 +1,41 @@
+import { useState, useEffect } from 'react';
+import Login from './components/Login';
+import Layout from './components/Layout';
+import Dashboard from './components/Dashboard';
+
+function App() {
+  const [token, setToken] = useState<string | null>(localStorage.getItem('token'));
+  const [searchQuery, setSearchQuery] = useState('');
+
+  useEffect(() => {
+    const savedToken = localStorage.getItem('token');
+    if (savedToken) {
+      setToken(savedToken);
+    }
+  }, []);
+
+  const handleLogin = (newToken: string) => {
+    setToken(newToken);
+  };
+
+  const handleLogout = () => {
+    localStorage.removeItem('token');
+    setToken(null);
+  };
+
+  const handleSearch = (query: string) => {
+    setSearchQuery(query);
+  };
+
+  if (!token) {
+    return <Login onLogin={handleLogin} />;
+  }
+
+  return (
+    <Layout onLogout={handleLogout} onSearch={handleSearch}>
+      <Dashboard searchQuery={searchQuery} />
+    </Layout>
+  );
+}
+
+export default App;