Fix multiblock parts not showing formed textures on world load

-  Added @persisted to controllerPositions in MultiblockPartMachine so controller references are available immediately on load
- Add onLoad() to rebuild controllers from persisted positions and
  clear IS_FORMED if controllers can't be resolved (prevents inconsistent visual state with overlays but no texture overrides)
- Fix MetaMachineBlockEntity.onLoad() to always intern() the render state after NBT load, ensuring it matches modelsByState keys

Author: Saereth

src/main/java/com/gregtechceu/gtceu/api/blockentity/MetaMachineBlockEntity.java

@@ -176,10 +176,15 @@ public void setRemoved() {
     @Override
     public void onLoad() {
         super.onLoad();
-        // Validate render state after NBT load - @Persisted writes directly to field via reflection,
-        // bypassing setRenderState(), so we need to validate here as well
-        if (renderState != null && !renderState.is(getDefinition())) {
-            this.renderState = correctRenderStateDefinition(renderState);
+        // Validate and intern render state after NBT load - @Persisted writes directly to field via reflection,
+        // bypassing setRenderState(), so we need to validate and intern here as well
+        if (renderState != null) {
+            if (!renderState.is(getDefinition())) {
+                this.renderState = correctRenderStateDefinition(renderState).intern();
+            } else {
+                // Ensure the state is properly interned even if definition is correct
+                this.renderState = renderState.intern();
+            }
         }
         metaMachine.onLoad();
     }

src/main/java/com/gregtechceu/gtceu/api/machine/multiblock/part/MultiblockPartMachine.java

@@ -12,6 +12,7 @@
 import com.gregtechceu.gtceu.api.machine.trait.RecipeHandlerList;
 
 import com.lowdragmc.lowdraglib.syncdata.annotation.DescSynced;
+import com.lowdragmc.lowdraglib.syncdata.annotation.Persisted;
 import com.lowdragmc.lowdraglib.syncdata.annotation.RequireRerender;
 import com.lowdragmc.lowdraglib.syncdata.annotation.UpdateListener;
 import com.lowdragmc.lowdraglib.syncdata.field.ManagedFieldHolder;
@@ -38,6 +39,7 @@ public class MultiblockPartMachine extends MetaMachine implements IMultiPart {
     protected static final ManagedFieldHolder MANAGED_FIELD_HOLDER = new ManagedFieldHolder(MultiblockPartMachine.class,
             MetaMachine.MANAGED_FIELD_HOLDER);
 
+    @Persisted
     @DescSynced
     @RequireRerender
     @UpdateListener(methodName = "onControllersUpdated")
@@ -114,6 +116,26 @@ protected RecipeHandlerList getHandlerList() {
         return handlerList;
     }
 
+    @Override
+    public void onLoad() {
+        super.onLoad();
+        // Rebuild controllers from persisted positions on load
+        // @UpdateListener only fires on sync updates, not on NBT load
+        if (!controllerPositions.isEmpty()) {
+            onControllersUpdated(controllerPositions, Collections.emptySet());
+            // If we couldn't resolve controllers (loading order or cross-chunk),
+            // clear the formed state to avoid inconsistent visuals (overlays without texture overrides).
+            // The async multiblock validation will restore formed state properly when ready.
+            if (controllers.isEmpty()) {
+                MachineRenderState renderState = getRenderState();
+                if (renderState.hasProperty(GTMachineModelProperties.IS_FORMED) &&
+                        renderState.getValue(GTMachineModelProperties.IS_FORMED)) {
+                    setRenderState(renderState.setValue(GTMachineModelProperties.IS_FORMED, false));
+                }
+            }
+        }
+    }
+
     @Override
     public void onUnload() {
         super.onUnload();