Fix o_voxel import: monkey-patch postprocess instead of sys.path override

app.py

@@ -6,9 +6,7 @@ from concurrent.futures import ThreadPoolExecutor
 import os
 import sys
 
-# Prioritize local o-voxel submodule (with cumesh.fill_holes() fix) over prebuilt wheel
 _script_dir = os.path.dirname(os.path.abspath(__file__))
-sys.path.insert(0, os.path.join(_script_dir, 'o-voxel'))
 
 os.environ["OPENCV_IO_ENABLE_OPENEXR"] = '1'
 os.environ["PYTORCH_CUDA_ALLOC_CONF"] = "expandable_segments:True"
@@ -31,6 +29,16 @@ from trellis2.renderers import EnvMap
 from trellis2.utils import render_utils
 import o_voxel
 
+# Patch postprocess module with local fix for cumesh.fill_holes() bug
+import importlib.util
+_local_postprocess = os.path.join(_script_dir, 'o-voxel', 'o_voxel', 'postprocess.py')
+if os.path.exists(_local_postprocess):
+    _spec = importlib.util.spec_from_file_location('o_voxel.postprocess', _local_postprocess)
+    _mod = importlib.util.module_from_spec(_spec)
+    _spec.loader.exec_module(_mod)
+    o_voxel.postprocess = _mod
+    sys.modules['o_voxel.postprocess'] = _mod
+
 
 MAX_SEED = np.iinfo(np.int32).max
 TMP_DIR = os.path.join(os.path.dirname(os.path.abspath(__file__)), 'tmp')