fix(config): handle UTF-8 BOM in config files on Windows (#499) (#500)

Windows text editors (Notepad, VS Code with certain settings) may save
UTF-8 files with a Byte Order Mark (BOM, U+FEFF). Opening such files
with encoding='utf-8' causes json.load() to fail because the BOM
character appears before the opening '{'.

Change encoding from 'utf-8' to 'utf-8-sig' in load_json_config().
Python's utf-8-sig codec automatically strips the BOM when present,
while behaving identically to utf-8 for BOM-less files.

Co-authored-by: r266-tech <r266-tech@users.noreply.github.com>

Author: r266-tech

openviking_cli/utils/config/config_loader.py

@@ -80,7 +80,7 @@ def load_json_config(path: Path) -> Dict[str, Any]:
     if not path.exists():
         raise FileNotFoundError(f"Config file does not exist: {path}")
 
-    with open(path, "r", encoding="utf-8") as f:
+    with open(path, "r", encoding="utf-8-sig") as f:
         try:
             print(f"Loading config file: {path}")
             return json.load(f)