Dodaj react-router-dom, mape tras i ProtectedRoute

Fundament migracji z useState(view) na prawdziwy routing:
- react-router-dom 7 w zaleznosciach
- BrowserRouter w main.tsx (nginx ma juz try_files, wiec czyste sciezki dzialaja)
- routes.ts: centralna mapa adresow + helpery listingPath/mapPath/adminTabPath
- ProtectedRoute z obsluga stanu loading z AuthProvider

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

frontend/src/main.tsx

@@ -1,15 +1,18 @@
 import React from 'react';
 import ReactDOM from 'react-dom/client';
+import { BrowserRouter } from 'react-router-dom';
 import App from './App';
 import { AuthProvider } from './auth';
 import { NotificationsProvider } from './notifications';
 
 ReactDOM.createRoot(document.getElementById('root')!).render(
   <React.StrictMode>
-    <AuthProvider>
-      <NotificationsProvider>
-        <App />
-      </NotificationsProvider>
-    </AuthProvider>
+    <BrowserRouter>
+      <AuthProvider>
+        <NotificationsProvider>
+          <App />
+        </NotificationsProvider>
+      </AuthProvider>
+    </BrowserRouter>
   </React.StrictMode>,
 );