fix(nodes): snapshot scanner cache before iterating on executor thread

Node code reads cache.raw_data while MetadataSyncService may mutate it
from a background thread; iterate over a list() snapshot to avoid a
possible 'list changed size during iteration' RuntimeError.

py/nodes/unet_loader.py

@@ -93,7 +93,7 @@ class UNETLoaderLM:
 
                 # Filter only diffusion_model type and format names
                 names = []
-                for item in cache.raw_data:
+                for item in list(cache.raw_data):
                     if item.get("sub_type") == "diffusion_model":
                         file_path = item.get("file_path", "")
                         # Only offer models that still exist on disk so ComfyUI
@@ -141,7 +141,7 @@ class UNETLoaderLM:
                 cache = await scanner.get_cached_data()
 
                 base_models = set()
-                for item in cache.raw_data:
+                for item in list(cache.raw_data):
                     if item.get("sub_type") != "diffusion_model":
                         continue
                     base_model = item.get("base_model")