def evaluate(case):
    """Return a dict with desired_binding, observation_state, drift_state, action_state,
    convergence_status, decision, audit_event, and reason.

    Use only visible synthetic evidence. Keep freshness, ownership, action execution,
    retry bounds, and observed convergence as separate gates.
    """
    raise NotImplementedError("Implement the LOC-016 desired-state reconciliation evidence contract")