reset method

void reset()

Reset to idle — called on sheet entry so a prior terminal result never lingers into a new shield. A NO-OP while a step is in flight ( review F1): re-opening the sheet mid-submit RE-ATTACHES to the running flow — clobbering the transient would make the identity guards swallow the landing outcome.

Implementation

void reset() {
  if (_inFlight) return;
  _set(const ShieldIdle());
}