Migrate to Telegram Navigator integration

Replace manual BackButton management with official @telegram-apps/react-router-integration
to fix navigation issues (back button cycling and double-click).

Changes:
- Migrate from @tma.js/sdk-react to @telegram-apps/sdk-react
- Downgrade react-router-dom to v6 for package compatibility
- Add AppWithNavigator component with Telegram navigator integration
- Use browser history mode (hashMode: null) to prevent hash URLs
- Add multi-level platform detection (user data, platform, version)
- Add try-catch error handling for navigator attach/detach
- Simplify useBackButton hook to no-op (navigator handles automatically)
- Update vite config with new Telegram packages

The navigator automatically manages BackButton based on router history,
falling back to BrowserRouter in regular browser environment.

src/AppWithNavigator.tsx

@@ -0,0 +1,102 @@
+import { useEffect, useMemo } from 'react';
+import { BrowserRouter, Router } from 'react-router-dom';
+import { useIntegration } from '@telegram-apps/react-router-integration';
+import { initNavigator } from '@telegram-apps/sdk';
+import App from './App';
+import { PlatformProvider } from './platform/PlatformProvider';
+import { ThemeColorsProvider } from './providers/ThemeColorsProvider';
+import { WebSocketProvider } from './providers/WebSocketProvider';
+import { ToastProvider } from './components/Toast';
+import { TooltipProvider } from './components/primitives/Tooltip';
+
+/**
+ * Check if running inside Telegram Mini App
+ * Uses multiple checks to reliably detect Telegram environment
+ */
+function isTelegramMiniApp(): boolean {
+  if (typeof window === 'undefined') return false;
+
+  const webApp = window.Telegram?.WebApp;
+  if (!webApp) return false;
+
+  // Check 1: initDataUnsafe should have user data in real Telegram
+  const hasUserData = webApp.initDataUnsafe?.user?.id !== undefined;
+
+  // Check 2: Platform should not be 'unknown' (which is default in browser)
+  const validPlatform = webApp.platform !== 'unknown' && webApp.platform !== '';
+
+  // Check 3: Version should be present (SDK loads in Telegram only)
+  const hasVersion = webApp.version !== undefined && webApp.version !== '';
+
+  return hasUserData || (validPlatform && hasVersion);
+}
+
+/**
+ * Component wrapper for Telegram navigator setup.
+ * Integrates Telegram Mini Apps navigator with React Router to provide
+ * automatic BackButton management based on navigation history.
+ * Falls back to BrowserRouter when not in Telegram Mini App.
+ */
+/**
+ * Navigator-based router for Telegram Mini App
+ */
+function TelegramRouter({ children }: { children: React.ReactNode }) {
+  const navigator = useMemo(() => initNavigator('app-navigation-state', { hashMode: null }), []);
+  const [location, reactNavigator] = useIntegration(navigator);
+
+  useEffect(() => {
+    try {
+      navigator.attach();
+      return () => {
+        try {
+          navigator.detach();
+        } catch (err) {
+          console.warn('Failed to detach navigator:', err);
+        }
+      };
+    } catch (err) {
+      console.warn('Failed to attach navigator:', err);
+    }
+  }, [navigator]);
+
+  return (
+    <Router location={location} navigator={reactNavigator}>
+      {children}
+    </Router>
+  );
+}
+
+export function AppWithNavigator() {
+  const isTelegram = useMemo(() => {
+    const result = isTelegramMiniApp();
+    console.log('[AppWithNavigator] Platform detection:', {
+      isTelegram: result,
+      platform: window.Telegram?.WebApp?.platform,
+      hasUser: window.Telegram?.WebApp?.initDataUnsafe?.user?.id !== undefined,
+      version: window.Telegram?.WebApp?.version,
+    });
+    return result;
+  }, []);
+
+  // Common app content
+  const appContent = (
+    <PlatformProvider>
+      <ThemeColorsProvider>
+        <TooltipProvider>
+          <ToastProvider>
+            <WebSocketProvider>
+              <App />
+            </WebSocketProvider>
+          </ToastProvider>
+        </TooltipProvider>
+      </ThemeColorsProvider>
+    </PlatformProvider>
+  );
+
+  // Use Telegram navigator in Mini App, BrowserRouter elsewhere
+  if (isTelegram) {
+    return <TelegramRouter>{appContent}</TelegramRouter>;
+  }
+
+  return <BrowserRouter>{appContent}</BrowserRouter>;
+}