Function implement 

pub fn implement(
    instruction: &str,
    cwd: &str,
    language: &str,
    brief: Option<&str>,
    attachments: &[PathBuf],
) -> String

Prompt for an implementer.

brief is the design-deliberation stage’s synthesis (crate::advise::Advice::synthesis), when the stage ran and at least one advisor’s proposal was usable. None when [graph] advise is off, the stage found nothing usable, or the synthesis seat itself failed - the implementer then gets exactly the prompt it always did.

attachments are absolute paths of files the task was filed with (screenshots, typically), which live outside the worktree. Empty leaves the prompt exactly as it always was.