feat: add Expo QR code generation and modal for mobile preview

Introduce Expo QR code functionality to allow users to preview their projects on mobile devices. Added a new QR code modal component, integrated it into the chat and preview components, and implemented Expo URL detection in the shell process. This enhances the mobile development workflow by providing a seamless way to test Expo projects directly on devices.

- Clean up and consolidate Preview icon buttons while removing redundant ones.

package.json

@@ -136,6 +136,7 @@
     "react-hotkeys-hook": "^4.6.1",
     "react-icons": "^5.4.0",
     "react-markdown": "^9.0.1",
+    "react-qr-code": "^2.0.15",
     "react-resizable-panels": "^2.1.7",
     "react-toastify": "^10.0.6",
     "react-window": "^1.8.11",