knowledge-base: retract an accepted record or its clauses on the operator's Approve

The operator prefers removing a wrong decision to stacking a correcting
record on it, and withdraw took only reserved or proposed records. retract
asks the operator through the router like a record that needs the operator,
and changes nothing until the Approve; a retracted record or clause no longer
holds in ask, holds, get, links and progress, history keeps every version, and
the whole-set rules still read a retracted record's links so a retraction alone
raises no finding. withdraw with retraction true takes a waiting one back.

modules/mesh-knowledge/cmd/mesh-knowledge/operator.go

@@ -245,6 +245,12 @@ func (k *KB) Reconcile() ([]string, error) {
 	}
 	var said []string
 	for _, e := range all {
+		if x := e.Current.Retracting; x != nil && x.Ask != nil && x.Ask.Said == AskWaiting {
+			if s := k.reconcileRetraction(ctx, e); s != "" {
+				said = append(said, s)
+			}
+			continue
+		}
 		w := e.Working()
 		if w.Status != StatusProposed || w.Ask == nil || w.Ask.Said != AskWaiting {
 			continue
@@ -366,6 +372,10 @@ func (k *KB) HeardEnd(w asks.Warrant) {
 		return
 	}
 	for _, e := range all {
+		if x := e.Current.Retracting; x != nil && x.Ask != nil && x.Ask.ID == w.Ask {
+			k.logf("[mesh-knowledge] %s", k.decideRetraction(ctx, e, w))
+			continue
+		}
 		r := e.Working()
 		if r.Ask != nil && r.Ask.ID == w.Ask && r.Ask.Said == AskWaiting {
 			k.logf("[mesh-knowledge] %s", k.decide(ctx, e, r, w))