ui: move vid_roll to top-right row, restore vid_hdri below vid_cam

app.py

@@ -776,15 +776,13 @@ def build_app() -> gr.Blocks:
 
                 with gr.Row():
                     mesh_view = gr.Model3D(label="① Geometry", height=250)
-                    vid_hdri = gr.Video(label="③ HDRI rotation",
+                    vid_roll = gr.Video(label="③ HDRI env roll",
                                         autoplay=True, loop=True, height=250)
 
                 vid_cam = gr.Video(label="③ Camera orbit",
                                     autoplay=True, loop=True, height=250)
-
-                with gr.Accordion("HDRI env roll", open=False):
-                    vid_roll = gr.Video(label="③ HDRI env roll",
-                                        autoplay=True, loop=True, height=180)
+                vid_hdri = gr.Video(label="③ HDRI rotation",
+                                    autoplay=True, loop=True, height=250)
 
             # ── RIGHT: examples sidebar ───────────────────────────────────────
             with gr.Column(scale=2, min_width=160, elem_classes=["sidebar-examples"]):