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/items/base/AdjustmentHelper.java

@@ -0,0 +1,173 @@
+package com.tiedup.remake.items.base;
+
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.util.Mth;
+import net.minecraft.world.item.ItemStack;
+
+/**
+ * Helper class for reading/writing adjustment values to ItemStack NBT.
+ *
+ * Adjustment values represent vertical offset in pixels (-4.0 to +4.0).
+ * These are stored in the ItemStack's NBT and automatically synced to clients
+ * via the equipment sync system (PacketSyncV2Equipment).
+ */
+public class AdjustmentHelper {
+
+    /** NBT key for Y adjustment value */
+    public static final String NBT_ADJUSTMENT_Y = "AdjustY";
+
+    /** NBT key for scale adjustment value */
+    public static final String NBT_ADJUSTMENT_SCALE = "AdjustScale";
+
+    /** Default adjustment value (no offset) */
+    public static final float DEFAULT_VALUE = 0.0f;
+
+    /** Minimum allowed adjustment value */
+    public static final float MIN_VALUE = -4.0f;
+
+    /** Maximum allowed adjustment value */
+    public static final float MAX_VALUE = 4.0f;
+
+    /** Minimum allowed scale value */
+    public static final float MIN_SCALE = 0.5f;
+
+    /** Maximum allowed scale value */
+    public static final float MAX_SCALE = 2.0f;
+
+    /** Default scale value (no scaling) */
+    public static final float DEFAULT_SCALE = 1.0f;
+
+    /** Scale adjustment step */
+    public static final float SCALE_STEP = 0.1f;
+
+    /**
+     * Get the Y adjustment value from an ItemStack.
+     *
+     * @param stack The ItemStack to read from
+     * @return adjustment in pixels (-4.0 to +4.0), or default if not set
+     */
+    public static float getAdjustment(ItemStack stack) {
+        if (stack.isEmpty()) {
+            return DEFAULT_VALUE;
+        }
+
+        CompoundTag tag = stack.getTag();
+        if (tag != null && tag.contains(NBT_ADJUSTMENT_Y)) {
+            return tag.getFloat(NBT_ADJUSTMENT_Y);
+        }
+
+        // Fallback to item's default adjustment
+        if (stack.getItem() instanceof IAdjustable adj) {
+            return adj.getDefaultAdjustment();
+        }
+
+        return DEFAULT_VALUE;
+    }
+
+    /**
+     * Set the Y adjustment value on an ItemStack.
+     * Value is clamped to the valid range.
+     *
+     * @param stack The ItemStack to modify
+     * @param value The adjustment value in pixels
+     */
+    public static void setAdjustment(ItemStack stack, float value) {
+        if (stack.isEmpty()) {
+            return;
+        }
+
+        float clamped = Mth.clamp(value, MIN_VALUE, MAX_VALUE);
+        stack.getOrCreateTag().putFloat(NBT_ADJUSTMENT_Y, clamped);
+    }
+
+    /**
+     * Check if an ItemStack has a custom adjustment set.
+     *
+     * @param stack The ItemStack to check
+     * @return true if a custom adjustment is stored in NBT
+     */
+    public static boolean hasAdjustment(ItemStack stack) {
+        if (stack.isEmpty()) {
+            return false;
+        }
+        CompoundTag tag = stack.getTag();
+        return tag != null && tag.contains(NBT_ADJUSTMENT_Y);
+    }
+
+    /**
+     * Remove custom adjustment from an ItemStack, reverting to item default.
+     *
+     * @param stack The ItemStack to modify
+     */
+    public static void clearAdjustment(ItemStack stack) {
+        if (stack.isEmpty()) {
+            return;
+        }
+        CompoundTag tag = stack.getTag();
+        if (tag != null) {
+            tag.remove(NBT_ADJUSTMENT_Y);
+        }
+    }
+
+    /**
+     * Convert pixel adjustment to Minecraft units for PoseStack.translate().
+     * 1 pixel = 1/16 block in Minecraft's coordinate system.
+     *
+     * Note: The result is negated because positive adjustment values should
+     * move the item UP (negative Y in model space).
+     *
+     * @param pixels Adjustment value in pixels
+     * @return Offset in Minecraft units for PoseStack.translate()
+     */
+    public static double toMinecraftUnits(float pixels) {
+        return -pixels / 16.0;
+    }
+
+    /**
+     * Check if an ItemStack's item supports adjustment.
+     *
+     * @param stack The ItemStack to check
+     * @return true if the item implements IAdjustable and canBeAdjusted() returns true
+     */
+    public static boolean isAdjustable(ItemStack stack) {
+        if (stack.isEmpty()) {
+            return false;
+        }
+        if (stack.getItem() instanceof IAdjustable adj) {
+            return adj.canBeAdjusted();
+        }
+        return false;
+    }
+
+    /**
+     * Get the scale adjustment value from an ItemStack.
+     *
+     * @param stack The ItemStack to read from
+     * @return scale factor (0.5 to 2.0), or 1.0 if not set
+     */
+    public static float getScale(ItemStack stack) {
+        if (stack.isEmpty()) {
+            return DEFAULT_SCALE;
+        }
+        CompoundTag tag = stack.getTag();
+        if (tag != null && tag.contains(NBT_ADJUSTMENT_SCALE)) {
+            return tag.getFloat(NBT_ADJUSTMENT_SCALE);
+        }
+        return DEFAULT_SCALE;
+    }
+
+    /**
+     * Set the scale adjustment value on an ItemStack.
+     * Value is clamped to the valid range.
+     *
+     * @param stack The ItemStack to modify
+     * @param value The scale value (0.5 to 2.0)
+     */
+    public static void setScale(ItemStack stack, float value) {
+        if (stack.isEmpty()) {
+            return;
+        }
+        float clamped = Mth.clamp(value, MIN_SCALE, MAX_SCALE);
+        stack.getOrCreateTag().putFloat(NBT_ADJUSTMENT_SCALE, clamped);
+    }
+}