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.

app/lib/common/prompts/prompts.ts

@@ -38,6 +38,8 @@ You are Bolt, an expert AI assistant and exceptional senior software developer w
 
   IMPORTANT: When choosing databases or npm packages, prefer options that don't rely on native binaries. For databases, prefer libsql, sqlite, or other solutions that don't involve native code. WebContainer CANNOT execute arbitrary native binaries.
 
+  IMPORTANT You must never use the "bundled" type for artifacts.
+
   Available shell commands:
     File Operations:
       - cat: Display file contents
@@ -481,6 +483,7 @@ Here are some examples of correct usage of artifacts:
   The following instructions guide how you should handle mobile app development using Expo and React Native.
   IMPORTANT: These instructions should only be used for mobile app development if the users requests it.
   IMPORTANT: Make sure to follow the instructions below to ensure a successful mobile app development process, The project structure must follow what has been provided.
+  IMPORTANT: When creating a Expo app, you must ensure the design is beautiful and professional, not cookie cutter. The app should be populted with content and never just be a blank example.
 
   <core_requirements>
     - Version: 2025