Function post_hook_stdout 

pub fn post_hook_stdout(
    shape: HookShape,
    session: Option<&str>,
) -> (String, Vec<String>)

Stdout for a tool-result hook, and the ids to mark now that the note was delivered. A runner that holds the prompt note takes whatever note is held. The file goes with that take, so a later tool in the same turn finds nothing and Stop has nothing to say. Skipping a new hold because an earlier note was echoed leaves that hold for Stop, and Stop additionalContext starts another round. A turn with no tool leaves the hold until Stop takes it. A camel-case runner does not print that take.