fix(git_helper): use sys.exit(1) and stderr for module-level validation errors

- exit(-1) → sys.exit(1): Windows displays -1 as unsigned 4294967295
- print() → print(file=sys.stderr): error messages belong on stderr
- Add f-string prefix to COMFYUI_PATH error message (variable was not interpolated)

Author: ltdrdata

comfyui_manager/common/git_helper.py

@@ -15,12 +15,12 @@
 git_exe_path = os.environ.get('GIT_EXE_PATH')
 
 if comfy_path is None:
-    print("git_helper: environment variable 'COMFYUI_PATH' is not specified.")
-    exit(-1)
+    print("git_helper: environment variable 'COMFYUI_PATH' is not specified.", file=sys.stderr)
+    sys.exit(1)
 
 if not os.path.exists(os.path.join(comfy_path, 'folder_paths.py')):
-    print("git_helper: '{comfy_path}' is not a valid 'COMFYUI_PATH' location.")
-    exit(-1)
+    print(f"git_helper: '{comfy_path}' is not a valid 'COMFYUI_PATH' location.", file=sys.stderr)
+    sys.exit(1)
 
 def download_url(url, dest_folder, filename=None):
     # Ensure the destination folder exists