Function idle_timeout_path 

pub fn idle_timeout_path(project_root: &Path, phase: PhaseId) -> PathBuf

Path to the pipe-owning monitor’s idle-timeout verdict for a phase (D-05/D-06, 31-02).

A SIDE CHANNEL, deliberately separate from the stdout capture: the capture is the agent’s own narration, and a verdict appended to it is shadowed by any earlier genuine result event the stream already contained. See [parse_idle_timeout_side_channel] — that separation is a correctness requirement (T-31-06), not a filing convention.

Holds a JSON IdleTimeoutRecord. Written and fsynced by the monitor BEFORE the child is signalled, so nothing can race the verdict.