Clean repo for open source release

Remove build artifacts, dev tool configs, unused dependencies,
and third-party source dumps. Add proper README, update .gitignore,
clean up Makefile.

src/main/java/com/tiedup/remake/client/events/EarplugSoundHandler.java

@@ -0,0 +1,91 @@
+package com.tiedup.remake.client.events;
+
+import com.tiedup.remake.client.MuffledSoundInstance;
+import com.tiedup.remake.core.ModConfig;
+import com.tiedup.remake.core.TiedUpMod;
+import com.tiedup.remake.state.PlayerBindState;
+import net.minecraft.client.Minecraft;
+import net.minecraft.client.player.LocalPlayer;
+import net.minecraft.client.resources.sounds.SoundInstance;
+import net.minecraft.sounds.SoundSource;
+import net.minecraftforge.api.distmarker.Dist;
+import net.minecraftforge.api.distmarker.OnlyIn;
+import net.minecraftforge.client.event.sound.PlaySoundEvent;
+import net.minecraftforge.eventbus.api.SubscribeEvent;
+import net.minecraftforge.fml.common.Mod;
+
+/**
+ * Client-side sound handler for earplugs effect.
+ *
+ * When the player has earplugs equipped, all sounds are muffled
+ * (volume reduced to simulate hearing impairment).
+ *
+ * Based on Forge's PlaySoundEvent to intercept and modify sounds.
+ */
+@OnlyIn(Dist.CLIENT)
+@Mod.EventBusSubscriber(
+    modid = TiedUpMod.MOD_ID,
+    bus = Mod.EventBusSubscriber.Bus.FORGE,
+    value = Dist.CLIENT
+)
+public class EarplugSoundHandler {
+
+    /** Pitch modifier to make sounds more muffled (much lower for "underwater" effect) */
+    private static final float MUFFLED_PITCH_MODIFIER = 0.6f;
+
+    /** Categories to always let through at normal volume (important UI feedback) */
+    private static final SoundSource[] UNAFFECTED_CATEGORIES = {
+        SoundSource.MASTER, // Master volume controls
+        SoundSource.MUSIC, // Music is internal, not muffled by earplugs
+    };
+
+    /**
+     * Intercept sound events and muffle them if player has earplugs.
+     */
+    @SubscribeEvent
+    public static void onPlaySound(PlaySoundEvent event) {
+        // Get the sound being played
+        SoundInstance sound = event.getSound();
+        if (sound == null) {
+            return;
+        }
+
+        // Check if player has earplugs
+        Minecraft mc = Minecraft.getInstance();
+        if (mc == null) {
+            return;
+        }
+        LocalPlayer player = mc.player;
+        if (player == null) {
+            return;
+        }
+
+        PlayerBindState state = PlayerBindState.getInstance(player);
+        if (state == null || !state.hasEarplugs()) {
+            return;
+        }
+
+        // Check if this sound category should be affected
+        SoundSource source = sound.getSource();
+        for (SoundSource unaffected : UNAFFECTED_CATEGORIES) {
+            if (source == unaffected) {
+                return; // Don't muffle this category
+            }
+        }
+
+        // Don't wrap already-wrapped sounds (prevent infinite recursion)
+        if (sound instanceof MuffledSoundInstance) {
+            return;
+        }
+
+        // Wrap the sound with our muffling wrapper
+        // The wrapper delegates to the original but modifies getVolume()/getPitch()
+        SoundInstance muffledSound = new MuffledSoundInstance(
+            sound,
+            ModConfig.CLIENT.earplugVolumeMultiplier.get().floatValue(),
+            MUFFLED_PITCH_MODIFIER
+        );
+
+        event.setSound(muffledSound);
+    }
+}