pub fn convert_skeleton_json_to_jsonl(
json_path: &Path,
title: Option<&str>,
last_message_date: Option<i64>,
) -> Result<Option<PathBuf>>Expand description
Convert a skeleton .json file to a valid minimal .jsonl file.
Preserves title and timestamp from the index entry if available.
The original .json file is renamed to .json.corrupt (non-destructive).
Returns the path to the new .jsonl file, or None if conversion was skipped.