Function detail_thread_lines 

fn detail_thread_lines<'a>(
    detail: &'a PatchsetDetail,
    palette: &'a ColorPalette,
    lines: &mut Vec<Line<'a>>,
)

Build thread message lines for the patchset detail view.

Each message in the patchset’s associated thread is rendered as two lines: author + date, then subject. This is a flat list — messages are rendered in API-returned order without indentation.