Two consumers may share a name; they must not share a delivery subject

novox/hq 04-ISSUES/146. A push consumer delivers onto an ordinary subject and
everything subscribed to it gets a copy. The controller holds a consumer called
'controller' on CONTROL and another called 'controller' on EVENTS, and both were
given _DELIVER.controller — so the one process, holding both subscriptions,
acted on every message twice.

Measured: one enrolment published, one message in the stream, one delivery, no
redelivery, and the controller enrolled the machine twice — the second minting a
credential that replaced the one the machine had just been handed, which is why
it then reconnected for ever as a user whose password the mesh had rotated. Every
report and every followed event doubled the same way, silently.

The stream goes in the subject because the pair is what identifies a consumer.
A subscriber's permission gains the same shape, keeping the bare name so an
existing consumer keeps working until the next assertion moves it.

internal/broker/nats.go

@@ -269,7 +269,13 @@ func PermissionsFor(p Principal) (Permissions, error) {
 			"mesh.control." + p.Node + ".>",
 			"$JS.API.CONSUMER.INFO.NODES." + p.Node,
 		}
-		sub = []string{"mesh.node." + p.Node + ".declare", "_DELIVER." + p.Node}
+		// The deliver subject carries the stream as well as the consumer's name, so what a
+		// subscriber is permitted has to carry it too (novox/hq 04-ISSUES/146). The bare name
+		// stays: an existing consumer keeps delivering where it always did until the controller's
+		// next assertion moves it, and a permission that only allowed the new shape would refuse
+		// every node in the mesh for exactly as long as that took.
+		sub = []string{"mesh.node." + p.Node + ".declare",
+			"_DELIVER." + p.Node, "_DELIVER." + p.Node + ".>"}
 
 	case KindModule:
 		// 1. Its own namespace: it publishes its events there and serves its tools there. Nothing
@@ -323,7 +329,7 @@ func PermissionsFor(p Principal) (Permissions, error) {
 			// take work over the new bus was refused the asking (2026-09-28).
 			worker := "SEAT_" + upperSnake(s.Name) + "_worker"
 			stream := seatStreamName(s.Name)
-			sub = append(sub, "_DELIVER."+worker)
+			sub = append(sub, "_DELIVER."+worker, "_DELIVER."+worker+".>")
 			pub = append(pub, "$JS.API.CONSUMER.INFO."+stream+"."+worker, "$JS.ACK."+stream+"."+worker+".>")
 			for _, a := range s.Accepts {
 				sub = append(sub, seatSubject(s, "accept", a))