Verify: camera may wedge in .cameraTransmittingVideo when 'send media to remote' is on

Unresolved contradiction — needs an experiment, not a fix. Do not change the code until this is decided; the reading and the observed behaviour disagree.

The reading

RemoteCam/SessionCoordinator.swift:936

case is UICmd.VideoResourceTransferCompleted, is UICmd.VideoResourceTransferFailed:
    ctrl?.cameraViewModel.finishVideoTransfer()

This shadows handleRoot:1058-1066 — the only code that emits StopRecordingVideoResp after a successful resource transfer:

case let completed as UICmd.VideoResourceTransferCompleted:
    monitor?.videoTransferFinished()
    if completed.success {
        await sendOrGoToScanning(RemoteCmd.StopRecordingVideoResp(sender: nil, pic: nil, error: nil))
    }

The camera can only leave .cameraTransmittingVideo via :939-945 (on StopRecordingVideoResp). On the send-video path the pipeline never produces one itself — RecordingPipeline.swift:185-190 only sends it in the else (don't-send-to-peer) branch; the send branch calls sendVideoAsResource. So by this reading the camera wedges after every send-video recording, in both directions, and the next StartRecordingVideo gets an error ack from handleRoot:1034-1035.

The contradiction

Recording twice in a row with the iPhone as camera reportedly works fine. The monitor hides a camera-side wedge because it rescues itself locally via didFinishReceivingResource (:2076-2096) — but the second recording should still fail, and it doesn't.

Most likely explanation: "send media to remote" is off, so RecordingPipeline.swift:189 answers directly and :936 is never exercised.

The deciding experiment

Coordinator test: seed .cameraTransmittingVideo, deliver UICmd.VideoResourceTransferCompleted(success: true), assert the camera sends RemoteCmd.StopRecordingVideoResp and returns to .camera.

• Fails → real bug; :936 must fall through to handleRoot (or emit the response itself).
• Passes → the reading is wrong and the model needs revisiting.

Manual counterpart: enable "send media to remote", record → stop → record again.

Context: RemoteCamTests/RemoteCamSessionTests.swift already seeds .cameraTransmittingVideo for the keyframe tests, so the harness exists.

Start with RemoteCam/SessionCoordinator.swift:936-945 and handleRoot:1034-1066, then inspect RecordingPipeline.swift:185-190. Add the described coordinator test in RemoteCamTests/RemoteCamSessionTests.swift, seeding .cameraTransmittingVideo and delivering VideoResourceTransferCompleted(success: true). Done means the test establishes whether StopRecordingVideoResp is sent and the state returns to .camera; optionally verify the manual two-recording path with sending enabled.