feat: migrate to @tma.js/sdk-react for Telegram Mini App

- Add useTelegramSDK hook with reactive signals for viewport, safe area, fullscreen
- Migrate TelegramAdapter to use SDK components (backButton, mainButton, hapticFeedback, cloudStorage, themeParams, popup)
- Update Login, TelegramRedirect to use SDK helpers
- Update PlatformProvider, api/client to use centralized SDK functions
- Simplify useTelegramWebApp as backward-compatible wrapper
- Add automatic CSS variable binding for theme and viewport

package.json

@@ -32,6 +32,7 @@
     "@radix-ui/react-tooltip": "^1.2.8",
     "@radix-ui/react-visually-hidden": "^1.2.4",
     "@tanstack/react-query": "^5.8.0",
+    "@tma.js/sdk-react": "^3.0.15",
     "axios": "^1.6.0",
     "class-variance-authority": "^0.7.1",
     "clsx": "^2.1.1",