feat(audio): add custom sound volume slider

HellionChat/Integrations/CustomAudioPlayer.cs

@@ -9,8 +9,9 @@ namespace HellionChat.Integrations;
 // WaveOutEvent/WinMM is the correct backend for FFXIV on Wine: it works
 // without Media Foundation (which Wine does not support for MP3/AAC).
 //
-// Volume is fixed at 0.8. No per-user slider in this iteration so we can
-// ship quickly and gather feedback before adding UX complexity.
+// Playback volume comes from Configuration.CustomSoundVolume via the Play
+// parameter, clamped to [0,1]. The 16 game sounds are unaffected — they go
+// through UIGlobals.PlaySoundEffect, which the plugin cannot scale.
 internal sealed class CustomAudioPlayer : IDisposable
 {
     // Sound bytes are read once at construction so each Play() wraps a fresh
@@ -55,7 +56,7 @@ internal sealed class CustomAudioPlayer : IDisposable
     // customIndex is 1, 2, or 3, matching the sound file suffix.
     // Stops any currently playing sound before starting the new one.
     // NAudio playback runs on its own thread; this method returns immediately.
-    public void Play(int customIndex)
+    public void Play(int customIndex, float volume)
     {
         if (customIndex < 1 || customIndex > 3)
         {
@@ -90,7 +91,10 @@ internal sealed class CustomAudioPlayer : IDisposable
                 // must be set after Init, otherwise waveOutSetVolume fails with
                 // InvalidHandle.
                 _outputDevice.Init(_reader);
-                _outputDevice.Volume = 0.8f;
+                // AUDIO-1: volume comes from Configuration.CustomSoundVolume.
+                // Clamp here too — a hand-edited config could carry an
+                // out-of-range value, and WaveOutEvent.Volume rejects those.
+                _outputDevice.Volume = Math.Clamp(volume, 0f, 1f);
                 _outputDevice.Play();
             }
             catch (Exception ex)