fix: previewbridge failure

https://github.com/ltdrdata/ComfyUI-Impact-Pack/issues/503#issuecomment-1977753647

modules/impact/bridge_nodes.py

@@ -2,9 +2,14 @@ import os
 from PIL import ImageOps
 from impact.utils import *
 
-from . import core
+# NOTE: this should not be `from . import core`.
+# I don't know why but... 'from .' and 'from impact' refer to different core modules.
+# This separates global variables of the core module and breaks the preview bridge.
+from impact import core
+# <--
 import random
 
+
 class PreviewBridge:
     @classmethod
     def INPUT_TYPES(s):

modules/impact/core.py

@@ -1,4 +1,3 @@
-import torch
 from segment_anything import SamPredictor
 
 from impact.utils import *