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/v2/blocks/ObjBlockEntity.java

@@ -0,0 +1,66 @@
+package com.tiedup.remake.v2.blocks;
+
+import javax.annotation.Nullable;
+import net.minecraft.core.BlockPos;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.resources.ResourceLocation;
+import net.minecraft.world.level.block.entity.BlockEntity;
+import net.minecraft.world.level.block.entity.BlockEntityType;
+import net.minecraft.world.level.block.state.BlockState;
+
+/**
+ * Base block entity for blocks that render with OBJ models.
+ * Subclasses define the model and texture locations.
+ */
+public abstract class ObjBlockEntity extends BlockEntity {
+
+    public ObjBlockEntity(
+        BlockEntityType<?> type,
+        BlockPos pos,
+        BlockState state
+    ) {
+        super(type, pos, state);
+    }
+
+    /**
+     * Get the OBJ model resource location.
+     * Example: "tiedup:models/obj/blocks/bowl/model.obj"
+     */
+    @Nullable
+    public abstract ResourceLocation getModelLocation();
+
+    /**
+     * Get the texture resource location.
+     * Example: "tiedup:textures/block/bowl.png"
+     */
+    @Nullable
+    public abstract ResourceLocation getTextureLocation();
+
+    /**
+     * Get the model scale (default 1.0).
+     * Override to scale the model up or down.
+     */
+    public float getModelScale() {
+        return 1.0f;
+    }
+
+    /**
+     * Get the model position offset (x, y, z).
+     * Override to adjust model position within the block.
+     */
+    public float[] getModelOffset() {
+        return new float[] { 0.0f, 0.0f, 0.0f };
+    }
+
+    @Override
+    protected void saveAdditional(CompoundTag tag) {
+        super.saveAdditional(tag);
+        // Subclasses can override to save additional data
+    }
+
+    @Override
+    public void load(CompoundTag tag) {
+        super.load(tag);
+        // Subclasses can override to load additional data
+    }
+}