broker: the substrate pre-declares a consumer's dead-lettered queue (ADR 0048)

LavinMQ refuses a non-administrator declaring a queue with a dead-letter
exchange, so a scoped module cannot make its own. EnsureModuleQueue declares
<node>.<module>.events with its DLX as the mesh, and 'module issue' does so
for a consuming module — the runtime then passively checks it rather than
declaring. Verified against a real broker: the scoped account binds and
consumes the pre-declared queue.

Claude-Session: https://claude.ai/code/session_01LrgweAeERJYBg88c5cKDzF

cmd/mesh-control/modules.go

@@ -243,6 +243,13 @@ func moduleCommand(ctx context.Context, args []string) error {
 		if err != nil {
 			return err
 		}
+		// A consumer's queue, with its dead-letter, is the substrate's to declare — its own account
+		// may not (ADR 0048). Made now, so it exists before the module binds onto it.
+		if len(m.Consumes) > 0 {
+			if err := management.EnsureModuleQueue(ctx, *forNode, module); err != nil {
+				return err
+			}
+		}
 
 		known, err := broker.FromEnvironment()
 		if err != nil {