Function stage_output_tail 

pub fn stage_output_tail(
    path: &Path,
    stage: &str,
    attempt: u32,
    lines: usize,
) -> Result<String>

The trailing lines lines one stage execution captured, decoded as text.

This is the only read that narrows to a single execution rather than a stage: it feeds the “previous attempt failed” block a re-entered agent stage is prompted with, and quoting a different attempt’s output there would send the agent after the wrong failure. Records written before attempts were tagged carry none and are claimed by the first attempt, which is the only one such a run ever had.