Lets a user transmit a second hardware input device (e.g. line-in / aux)
alongside the mic, with its own device picker and volume, from Audio Settings.
No core/ABI/proto changes: the aux is a VC_STREAM_AUX_DEVICE stream started
with external_feed=1 and fed via vc_stream_feed_pcm (the same external-feed
pipeline screen-audio uses). Per-kind local_streams_ already allows mic +
screen + one aux to coexist; volume is a client-side gain multiply (the core's
vc_set_input_gain is mic-only/global). Aux is always-on (core never gates
AUX_DEVICE on VAD/PTT) and is tied to the voice session.
Windows: new Audio/InputDeviceCapture.cs (WASAPI shared-mode capture from a
real input endpoint + capture-endpoint enumeration); aux section in
AudioSettingsForm.cs; lifecycle in MainForm.cs; persistence in VoiceSettings.cs.
macOS: new Audio/InputDeviceCapture.swift (AVAudioEngine input-node tap pinned
to the chosen Core Audio device + device enumeration by stable UID); aux section
in SettingsWindowController.swift; lifecycle + UserDefaults persistence in
MainWindowController.swift; file registered in project.pbxproj.
Windows verified (C# solution builds clean; aux confirmed working). macOS build
+ E2E pending a Mac.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Audio input settings (device picker, VAD/PTT mode, VAD sensitivity, mic gain,
PTT key) move from the always-visible bottom panel into Settings > Audio...,
matching the macOS/iOS pattern.
The device ComboBox now uses DataSource + DisplayMember="Name" instead of
Items.Add() with no DisplayMember — this fixes both the display bug (was
showing the full DeviceInfo record ToString()) and the NVDA silence on
dropdown open (DataSource binding exposes proper MSAA text per item).
Changes apply live for immediate feedback; Cancel reverts. VoiceSettings
gains InputDeviceId to persist the chosen device across sessions.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
