Make a seat pass no repair, read every machine before passing, keep the gate's pass in memory (issue 1317, review round 1)

cmd/mesh-controller/handacts.go

@@ -72,6 +72,10 @@ var handActVerbs = []handActVerb{
 	// An act the operator chose on a warrant (novox/hq ADR 0259): asked by the controller, answered on a
 	// channel that proved who answered, performed by the controller as itself.
 	{Verb: handActWarrant, Decision: "the operator chose it, answering what the controller asked (ADR 0259)"},
+	// A seat passed by the controller to its only claimant when its holder on record left (novox/hq ADR 0449
+	// §4): the mesh working as decided. A person's own `seat --to` is not recorded under this cause.
+	{Verb: "seat", Decision: "the controller passes a seat held once to its only claimant when its recorded " +
+		"holder is assigned nowhere (ADR 0449 §4)", DecidedFor: []string{"seat-passed"}},
 	{Verb: "broker consumer-reset"},
 	// Silencing the same condition twice says the condition, or what it watches, wants mending — unless
 	// it is the operator's answer on a notification: a decision to live with it (novox/hq ADR 0258).