Fix WebGL Context Lost when loading projects due to React Strict Mode unmount

src/pages/Editor.tsx

@@ -296,21 +296,21 @@ export default function Editor() {
   }, [blobURLs]);
 
   // Dispose old model when new one is loaded
+  const prevLoadedModelRef = useRef<THREE.Object3D | null>(null);
   useEffect(() => {
-    return () => {
-      if (loadedModel) {
-        loadedModel.traverse((child) => {
-          if (child instanceof THREE.Mesh) {
-            child.geometry.dispose();
-            if (Array.isArray(child.material)) {
-              child.material.forEach(m => m.dispose());
-            } else {
-              child.material.dispose();
-            }
+    if (prevLoadedModelRef.current && prevLoadedModelRef.current !== loadedModel) {
+      prevLoadedModelRef.current.traverse((child) => {
+        if (child instanceof THREE.Mesh) {
+          child.geometry.dispose();
+          if (Array.isArray(child.material)) {
+            child.material.forEach(m => m.dispose());
+          } else {
+            child.material.dispose();
           }
-        });
-      }
-    };
+        }
+      });
+    }
+    prevLoadedModelRef.current = loadedModel;
   }, [loadedModel]);
   const [isLoading, setIsLoading] = useState(false);
   const [importProgress, setImportProgress] = useState(0);