feat(audio): add custom sound volume slider

HellionChat/Ui/SettingsTabs/General.cs

@@ -95,6 +95,24 @@ internal sealed class General : ISettingsTab
         {
             ImGui.Checkbox(Language.Options_PlaySounds_Name, ref Mutable.PlaySounds);
             ImGuiUtil.HelpMarker(Language.Options_PlaySounds_Description);
+            // Volume is stored as a 0-1 float but shown as 0-100% to match user
+            // intuition. Full range — unlike opacity there is no unsafe floor.
+            var customSoundVolumePercent = Mutable.CustomSoundVolume * 100f;
+            if (
+                ImGuiUtil.DragFloatVertical(
+                    HellionStrings.Settings_General_CustomSoundVolume_Name,
+                    ref customSoundVolumePercent,
+                    1f,
+                    0f,
+                    100f,
+                    $"{customSoundVolumePercent:N0}%%",
+                    ImGuiSliderFlags.AlwaysClamp
+                )
+            )
+            {
+                Mutable.CustomSoundVolume = customSoundVolumePercent / 100f;
+            }
+            ImGuiUtil.HelpMarker(HellionStrings.Settings_General_CustomSoundVolume_Description);
 
             ImGui.Checkbox(Language.Options_ShowNoviceNetwork_Name, ref Mutable.ShowNoviceNetwork);
             ImGuiUtil.HelpMarker(Language.Options_ShowNoviceNetwork_Description);

HellionChat/Ui/SettingsTabs/Tabs.cs

@@ -234,7 +234,7 @@ internal sealed class Tabs : ISettingsTab
                     }
                     else
                     {
-                        Plugin.CustomAudioPlayer.Play((int)previewId - 16);
+                        Plugin.CustomAudioPlayer.Play((int)previewId - 16, Mutable.CustomSoundVolume);
                     }
                 }
             }