Visual capture falls back to audio-only silently, so the user couldn't tell if
it attached on a real call. SessionInfo now carries visualSegmentCount (nil =
audio-only; a count = visual ran, with that many vision-detected speaker
segments), shown in the menu as '… · N visual segments' or '… · audio-only'.
Makes the pending live-call validation unambiguous.
AudioRecorder captures system audio (ScreenCaptureKit) + mic (AVAudioEngine) on a
single serial ioQueue, one shared monotonic t0, time-driven writers (pad gaps /
trim overlaps) so tracks stay aligned, and an energy mic-VAD for 'self' spans.
AudioMixer sums the aligned tracks into mixed_mono_16k.wav. SessionController
drives a serialized start/stop state machine, writes the session folder +
self_vad.json, exposes live level meters, and finalizes on quit.
Hardening from review: ioQueue single-domain (no races), stop() never hangs
(mic-first teardown + bounded stopCapture), layout-agnostic mic deep-copy,
discard-only video output to keep SCStream alive, VAD lockstep on committed
frames, stable signing team in project.yml, single-instance enforcement.
Grant Gilliam