Fix: TRAX meter reflection — remove double attenuation from slider+loopback

Services/Audio/AudioGainProvider.cs

@@ -28,6 +28,8 @@ public sealed class AudioGainProvider
     /// <summary>Mic gain for the live mix (0 = muted).</summary>
     public double MicGain() => _micMuted() ? 0 : _micVolume();
 
-    /// <summary>Loopback (desktop/game) gain for the live mix (0 = muted).</summary>
-    public double LoopbackGain() => _gameMuted() ? 0 : _gameVolume();
+    /// <summary>Loopback (desktop/game) gain for the live mix (0 = muted, 1 = unity).
+    /// Unity because the slider now drives system volume via PushSystemVolume,
+    /// so the WASAPI loopback signal is already scaled by the user's volume choice.</summary>
+    public double LoopbackGain() => _gameMuted() ? 0 : 1.0;
 }

Services/Audio/AudioMixer.cs

@@ -10,8 +10,8 @@ namespace ytLive.Services.Audio;
 /// through the voice chain (bass → treble → noise gate → compressor), THEN
 /// level-metered and queued; loopback samples are resampled to 48 kHz stereo
 /// and queued. While live (<see cref="StartLive"/>), a 10 ms loop drains both
-/// queues, applies the honest gains (mic = MicVolume, loopback = GameAudioVolume
-/// × auto-duck when the mic is hot), mixes them to stereo float, runs the
+/// queues, applies the honest gains (mic = MicVolume, loopback = unity
+/// × auto-duck when the mic is hot — the slider drives system volume via mixes them to stereo float, runs the
 /// master limiter (a -1 dBFS ceiling so the sum never clips the encoder), and
 /// writes the chunk to the encoder's audio pipe.
 /// </summary>