fix: sync billboard texture in ThreeSixtyViewer on manual slider scrub

src/components/ThreeSixtyViewer.vue

@@ -144,8 +144,16 @@ const syncCameraToFrame = (frameIndex: number) => {
     );
   }
   controls.update();
+
+  // Sync texture for Three.js billboard
+  const activeImg = preloadedImages.value[frameIndex];
+  if (activeImg && billboardTexture) {
+    billboardTexture.image = activeImg;
+    billboardTexture.needsUpdate = true;
+  }
 };
 
+
 // Helper: match camera rotation back to closest frame texture
 const matchCameraToFrame = () => {
   if (!camera || !projectMetadata.value) return;