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/manifest_test.go

@@ -64,7 +64,7 @@ func TestItDeclaresAndHoldsTheKnowledgeBaseSeatOnceForTheMesh(t *testing.T) {
 	}
 	// ADR 0290 rule 6's verbs and those added after it; progress says a design's state, which ADR 0424 §1 makes the
 	// knowledge base's to work out (novox/hq issue 1947).
-	if !reflect.DeepEqual(Verbs, []string{"ask", "get", "list", "findings", "holds", "links", "history", "reserve", "propose", "import", "return", "withdraw", "progress"}) {
+	if !reflect.DeepEqual(Verbs, []string{"ask", "get", "list", "findings", "holds", "links", "history", "reserve", "propose", "import", "return", "withdraw", "retract", "progress"}) {
 		t.Fatalf("the verbs are not ADR 0290 rule 6's and those added after it: %v", Verbs)
 	}
 	if !reflect.DeepEqual(m.Emits, Events) {