Function newest_worker_session 

pub fn newest_worker_session(
    config_dir: &Path,
    run_dir: &Path,
    label: &str,
    project: &str,
    tag_cache: Option<&SessionTagCache>,
) -> Result<Option<(String, bool)>, TranscriptError>

The newest transcript in run_dir’s directory that carries label’s worker tag AND was tagged by project: its session id and whether its row predates the project field (true means the adopting project must stamp it). None when the directory holds no match.

The tag is what says whose session a transcript is, not the directory: everything that ran with that cwd writes there, the worker’s own subagents included, so the newest file in the directory is often not the worker’s. The project (the tag row’s project field) is the second half: the composed worktree directory is shared across a repository’s projects, so a label alone would let another project resume this session. A tag row written before the field existed carries no project and stays eligible, flagged so the caller can bound the window to one adoption.