Function run_recall 

pub fn run_recall(db_dir: &Path, hook_stdin: &str) -> String

The hook body: the nudge for the change in progress, or the digest for the prompt’s own identifiers, or nothing.

A prompt naming nothing code-shaped ends the hook here, before the store is even opened. The nudge is about the checkout rather than about what was typed, so it would be tempting to let it answer anyway — but this fires before every prompt, and “ok thanks” on a dirty tree is not a question about the diff. The prompt itself is passed on as the user typed it: recall_digest asks the same question again of the text it searches, and the two must not be able to disagree.