Fix channel lowpass source shadow

docs/agent-handoff.md

@@ -25,6 +25,7 @@ The Gitea runner has been used for:
 - Updated the `ExplosionMixin` complex constructor injection descriptor for Minecraft `1.21.1` after a client bootstrap crash showed the old Forge `1.20.1` constructor target no longer exists.
 - Updated `GameRendererBlurMixin` render callback and invoke descriptors for Minecraft `1.21.1` after the next client crash showed `GameRenderer#render` now receives `DeltaTracker, boolean`.
 - Replaced client tick subscriber parameters that used the temporary `compat.TickEvent.ClientTickEvent` placeholder with NeoForge `ClientTickEvent.Post` after mod loading rejected non-Event subscriber parameters.
+- Updated `ChannelLowpassMixin` to shadow `Channel#source` instead of the old obfuscated `f_83642_` field after the sound engine failed to apply the mixin.
 - Fixed runner setup issues:
   - executable `gradlew`
   - tracked `gradle-wrapper.jar`
@@ -38,6 +39,7 @@ The Gitea runner has been used for:
 | `git diff --check` | PASS after NeoForge `21.1.225` metadata change and `ExplosionMixin` runtime crash fix |
 | `git diff --check` | PASS after `GameRendererBlurMixin` runtime crash fix |
 | `git diff --check` | PASS after client tick subscriber event migration |
+| `git diff --check` | PASS after `ChannelLowpassMixin` source field migration |
 | Gitea decompile workflow | PASS |
 | Gitea build workflow | FAIL, now reaches Java API migration errors |
 
@@ -69,6 +71,7 @@ The remaining failures are real Forge-to-NeoForge/API-porting work, not runner s
 5. Retest the client jar after the `ExplosionMixin` descriptor fix; the next crash, if any, should be a later runtime/API issue rather than the bootstrap constructor mismatch.
 6. Retest the client jar after the `GameRendererBlurMixin` descriptor fix; the next crash, if any, should be the next stale mixin/API target.
 7. Retest the client jar after the client tick event migration; the next crash, if any, should be a later mod-loading/runtime issue.
+8. Retest the client jar after the `ChannelLowpassMixin` source field migration; watch for remaining audio mixin/accessor issues.
 
 ## Risks
 

src/main/java/com/vinlanx/explosionoverhaul/mixin/ChannelLowpassMixin.java

@@ -18,7 +18,7 @@ import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
 public class ChannelLowpassMixin {
     @Shadow
     @Final
-    private int f_83642_;
+    private int source;
 
     @Inject(method={"play"}, at={@At(value="HEAD")})
     private void onPlay(CallbackInfo ci) {
@@ -28,7 +28,7 @@ public class ChannelLowpassMixin {
                 SoundEngineAudioQueue.drainNow();
             }
             if (active) {
-                SoundEngineAudioQueue.enqueueAudio(() -> LowPassConcussionEffect.attachFilterToSource(this.f_83642_));
+                SoundEngineAudioQueue.enqueueAudio(() -> LowPassConcussionEffect.attachFilterToSource(this.source));
                 if ("Sound engine".equals(Thread.currentThread().getName())) {
                     SoundEngineAudioQueue.drainNow();
                 }
@@ -42,10 +42,10 @@ public class ChannelLowpassMixin {
     @Inject(method={"stop"}, at={@At(value="HEAD")})
     private void onStop(CallbackInfo ci) {
         if (SoundPhysicsCompatibility.isCompatibilityEnabled()) {
-            SoundPhysicsCompatibility.onSourceStop(this.f_83642_);
+            SoundPhysicsCompatibility.onSourceStop(this.source);
         }
         try {
-            SoundEngineAudioQueue.enqueueAudio(() -> LowPassConcussionEffect.detachFilterFromSource(this.f_83642_));
+            SoundEngineAudioQueue.enqueueAudio(() -> LowPassConcussionEffect.detachFilterFromSource(this.source));
             if ("Sound engine".equals(Thread.currentThread().getName())) {
                 SoundEngineAudioQueue.drainNow();
             }