Function is_task_notice 

pub fn is_task_notice(text: &str) -> bool

Whether a turn’s text is the harness’s own task notice rather than anything a person said: the marker the CLI writes at the head of the XML.

Two carriers hold it - the attachment row the scan hoists into a queued_command block, and a user row whose content string is the XML - and the fold reads the marker out of both, so a third shape would arrive here and not elsewhere.