NucleicandClaude Opus 4.8
07b6769410
Root cause (from on-device logs): the session was started from viewDidLoad while the pairing sheet was still presenting, so iOS interrupted it with reason 1 (videoDeviceNotAvailableInBackground) and it never ran (isRunning=false) — a black preview. The CMVideoFormatDescription -12710 errors were unrelated noise. Defer startRunning until the camera can actually run: configure the graph up front, then start only once the view is on screen and the app is foreground-active (viewDidAppear + a guarded startSessionIfReady). Recover on AVCaptureSessionInterruptionEnded / didBecomeActive / runtimeError. All start triggers funnel through the session queue and no-op if already running, so it's idempotent. Co-Authored-By: Claude Opus 4.8 <[email protected]>