Update cha_json.py

cha_json.py

@@ -298,6 +298,11 @@ def parse_args():
     p.add_argument("--output", "-o", type=str, required=True, help="輸出 .json 檔")
     return p.parse_args()
 
+def cha_to_json_path(cha_path: str, output_json: str | None = None) -> str:
+    """Backward-compatible alias for old code."""
+    out, _ = cha_to_json_file(cha_path, output_json=output_json)
+    return out
+
 def main():
     args = parse_args()
     in_path  = Path(args.input)