Update to Minecraft 1.26.1

Still one TODO left, but around data fixers, so fairly small.

 - GUI rendering got a big overhaul. I avoided the worst of it with
   9272e2efcd, but things like terminals
   and printouts still require some custom rendering.

 - Item models are now de-duplicated when rendering in the UI, so we
   need to keep track of their identity with
   (appendModelidentityElement). I'm not sure I've got this entirely
   right — whole thing feels unfortunately error-prone.

 - BE serialisation now goes through a Value{Input,Output} class, rather
   than using NBT directly. Fairly simple change, but has changed the
   format of the GameProfile used in turtle's owners. Need a DFU patch
   for this.

projects/common-api/src/client/java/dan200/computercraft/api/client/turtle/BasicUpgradeModel.java

@@ -61,6 +61,10 @@ public final class BasicUpgradeModel implements TurtleUpgradeModel {
 
     @Override
     public void renderForItem(UpgradeData<ITurtleUpgrade> upgrade, TurtleSide side, ItemStackRenderState renderer, ItemModelResolver resolver, ItemTransform transform, int seed) {
+        renderer.appendModelIdentityElement(this);
+        renderer.appendModelIdentityElement(side);
+        renderer.appendModelIdentityElement(transform);
+
         var layer = renderer.newLayer();
         layer.setTransform(transform);
         getModel(side).setupItemLayer(layer);

projects/common-api/src/client/java/dan200/computercraft/api/client/turtle/ItemUpgradeModel.java

@@ -26,8 +26,11 @@ import net.minecraft.util.Mth;
 import net.minecraft.world.item.ItemDisplayContext;
 import net.minecraft.world.item.ItemStack;
 import org.joml.Matrix4f;
+import org.joml.Vector3f;
 import org.jspecify.annotations.Nullable;
 
+import java.util.Set;
+
 /**
  * A sic {@link TurtleUpgradeModel} that renders the upgrade's {@linkplain ITurtleUpgrade#getUpgradeItem(DataComponentPatch)
  * upgrade item}.
@@ -59,9 +62,14 @@ public final class ItemUpgradeModel implements TurtleUpgradeModel {
 
     @Override
     public void renderForItem(UpgradeData<ITurtleUpgrade> upgrade, TurtleSide side, ItemStackRenderState renderer, ItemModelResolver resolver, ItemTransform transform, int seed) {
+        renderer.appendModelIdentityElement(this);
+
         var childState = new ItemStackRenderState();
         resolver.updateForTopItem(childState, upgrade.getUpgradeItem(), ItemDisplayContext.NONE, null, null, seed);
         if (!childState.isEmpty()) {
+            renderer.appendModelIdentityElement(childState.getModelIdentity());
+            renderer.appendModelIdentityElement(transform);
+
             var layer = renderer.newLayer();
             layer.setTransform(transform);
             layer.setupSpecialModel(getRenderer(side), childState);
@@ -122,6 +130,10 @@ public final class ItemUpgradeModel implements TurtleUpgradeModel {
             poseStack.popPose();
         }
 
+        @Override
+        public void getExtents(Set<Vector3f> set) {
+        }
+
         @Override
         public @Nullable ItemStackRenderState extractArgument(ItemStack itemStack) {
             return null;

projects/common-api/src/client/java/dan200/computercraft/api/client/turtle/TurtleUpgradeModel.java

@@ -57,6 +57,9 @@ public interface TurtleUpgradeModel {
 
     /**
      * Render this upgrade to an {@link ItemStackRenderState}. This is used for rendering the item form of the upgrade.
+     * <p>
+     * Like with {@link ItemModel}, implementations must be careful to call {@link ItemStackRenderState#appendModelIdentityElement}
+     * where appropriate.
      *
      * @param upgrade   The upgrade being rendered.
      * @param side      Which side of the turtle (left or right) the upgrade is equipped on.