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/entities/ISkinnedEntity.java

@@ -0,0 +1,27 @@
+package com.tiedup.remake.entities;
+
+import net.minecraft.resources.ResourceLocation;
+
+/**
+ * Interface for entities that provide their own skin texture.
+ *
+ * <p>This interface eliminates instanceof cascades in renderers by allowing
+ * each entity subclass to define its own texture logic polymorphically.
+ *
+ * <p><b>Issue #19:</b> DamselRenderer had 6+ instanceof checks to determine
+ * which texture method to call. With this interface, the renderer simply calls
+ * {@link #getSkinTexture()} and each entity type returns the appropriate texture.
+ *
+ * @see DamselRenderer
+ */
+public interface ISkinnedEntity {
+    /**
+     * Get the skin texture for this entity.
+     *
+     * <p>Implementations should return the appropriate texture based on
+     * the entity's current state (variant, skin selection, etc.).
+     *
+     * @return The texture ResourceLocation, never null
+     */
+    ResourceLocation getSkinTexture();
+}