Summary

This PR resolves the iOS camera permission handling issue in the mobile QR scanner screen. Previously, when the camera permission status was undetermined (-1), the screen assumed permission was granted and mounted the native Camera component. If the user subsequently denied permission in the iOS system dialog, the scanner area stayed blank without showing any error feedback or prompt to re-enable permissions in settings.

With this change, permission is requested programmatically first. If denied, the UI correctly transitions to a placeholder screen with a button that triggers a settings redirect dialog.

Closes : #610

Type of Change

• Bug fix
• New feature
• Refactor (no functional change)
• UI / Design change
• Tests only
• Documentation
• Infrastructure / DevOps
• Security

What Changed

• apps/mobile/src/screens/ScanScreen.tsx:
  • Imported Linking, AppState, AppStateStatus, and NativeModules from react-native.
  • Added a checkInitialCameraPermission function to check status and prompt for authorization programmatically using RNCameraKitModule if status is undetermined (-1).
  • Updated requestCameraPermission to show a user-friendly alert on iOS if permissions are denied, with a redirect link directly to iOS App Settings.
  • Added an AppState listener to automatically re-evaluate camera permission status when the user returns to the app from iOS Settings.
  • Fixed an ESLint warning for an unused err variable in handleSaveQR.

How to Test

1. Open the mobile app on iOS.
2. Navigate to the Scan screen.
3. Deny camera permission when the iOS system dialog prompts.
4. Verify that the app shows the "Camera Permission Required" placeholder instead of a blank black screen.
5. Tap "Grant Permission" and click "Settings" to verify that the app redirects you to the iOS settings menu.

Checklist

• My code follows the project's coding style (npm run lint passes).
• TypeScript compiles without errors (npm run typecheck --workspaces --if-present).
• I have added or updated tests for the changes I made.
• All tests pass locally (npm run test --workspaces --if-present).
• I have updated documentation where necessary.
• No new console.log or debug statements left in the code.
• Breaking changes are documented in this PR description.