fix(io): create parent directory before writing config tmp file

On first launch the app data directory does not exist yet, so the
atomic-write temp file open fails with ENOENT and logs an ERROR.

Author: vagabondHustler

src/subsearch/io/json_file.py

@@ -23,6 +23,7 @@ def load_json_value(json_file_path: Path, key: str) -> Any:
 def dump_json_data(json_file_path: Path, json_data: dict) -> None:
     temp_file_path = json_file_path.with_suffix(f"{json_file_path.suffix}.tmp")
     try:
+        json_file_path.parent.mkdir(parents=True, exist_ok=True)
         with open(temp_file_path, "w", encoding="utf-8") as file:
             json.dump(json_data, file, indent=2, ensure_ascii=False)
             file.flush()