feat(shutdown): implement graceful shutdown for camera session

[EthanDM]

What

Fix the navigation freeze on React Navigation/Fabric by shutting the camera session down deterministically when the view unmounts.

Changes

• Add CameraSession.shutdown, which disables photo/video/audio/code-scanner/location/torch before flipping isActive = false, and clears delegates while removing outputs.
• Stop both capture sessions asynchronously during CameraSession.deinit as a backstop.
• Have CameraView call the shutdown helper on unmount/deinit, log if teardown exceeds 2 s, and guard against concurrent shutdowns.

Tested on

• iPhone 14 Pro (iOS 26.0.1) with code scanner enabled, navigating away from the camera screen (no freeze).

Related issues

• Fixes 🐛 Navigating away on React Native 0.78+, XCode 26, and React Native Vision Camera v4.7.1 freezes the app #3636

[vercel]

@EthanDM is attempting to deploy a commit to the mrousavy's Team Team on Vercel.

A member of the Team first needs to authorize it.