Step 5.4 was wrong from 0119 onward; removed

It waited on a retirement condition 0119 abolished when it made the
deprecated broker an ordinary provider. A step waiting for a condition
nobody set would sit open forever.

03-DESIGN/01-to-be/28-building-the-bus.md

@@ -379,11 +379,20 @@ reserves them for after the move, and a flow built ahead of its design would be
       client still connected throughout
 - [ ] 5.2 the rollout: accounts composed, then the controller, every host and every runtime
       together; every node confirmed heard before AMQP stops
-- [ ] 5.3 the mesh's accounts removed from the deprecated broker, leaving the predecessor's users
+- [ ] 5.3 the mesh's own accounts removed from the deprecated broker: after the rollout nothing
-- [ ] 5.4 the deprecated broker retires when its condition holds — no client connected for the
+      of the mesh speaks to it, and an account nothing uses is one nobody rotates
-      period the operator sets
 
-**Done when.** Every node reports on NATS and the predecessor's clients never noticed.
+> **5.4 is gone, and was wrong from ADR 0119 onward.** It read "the deprecated broker retires
+> when its condition holds — no client connected for the period the operator sets", which is
+> ADR 0106's framing of it as a compatibility module with an end date.
+> [ADR 0119](../../02-DECISIONS/0119-amqp-is-a-provision-not-the-bus.md) settled that it is an
+> **ordinary provider** of the `amqp` provision, like any module answering a backing service:
+> no seat, not foundation, and **no retirement condition**, because the day its last client
+> disappears is not a day anything is waiting for. Removed rather than reworded — a step that
+> waits for a condition nobody set would sit open forever.
+
+**Done when.** Every node reports on NATS, and nothing of the mesh's own is left connected to the
+deprecated broker.
 
 ## The through-line