Increase apply_texture GPU duration to 600s; use 512px UV in CPU fallback

CPU xatlas texture bake takes ~5-10 min for a dense mesh, exceeding the
old duration=300 limit and causing GPU task abort. Also reduce fallback
uv_size from 1024 to 512 to halve bake time (~4x fewer texels).

app.py

@@ -1024,7 +1024,7 @@ def _bake_texture_cpu(glb_path: str, mv_views: list, out_path: str,
 
 # ── Stage 2: Texture ──────────────────────────────────────────────────────────
 
-@spaces.GPU(duration=300)
+@spaces.GPU(duration=600)
 def apply_texture(glb_path, input_image, remove_background, variant, tex_seed,
                   enhance_face, rembg_threshold=0.5, rembg_erode=2,
                   progress=gr.Progress()):
@@ -1189,7 +1189,7 @@ def apply_texture(glb_path, input_image, remove_background, variant, tex_seed,
             # Fallback: CPU xatlas UV-unwrap + per-face numpy projection
             print(f"[apply_texture] nvdiffrast baking failed ({type(_nv_err).__name__}): {_nv_err}")
             print("[apply_texture] Falling back to CPU xatlas texture bake...")
-            _bake_texture_cpu(glb_path, mv_views, out_glb)
+            _bake_texture_cpu(glb_path, mv_views, out_glb, uv_size=512)
 
         final_path = "/tmp/triposg_textured.glb"
         shutil.copy(out_glb, final_path)