The bus is the mesh's centre, not a transport that replaced one

Two things. A paragraph from the superseded 0117 survived beside the 0119
correction that reversed it, so §5 said both that the amqp interface
retires and that it does not. The stale one is gone.

And the framing. §1 opened with "the bus carries five kinds of traffic
today, and this design keeps the five", with a column mapping each to the
queue it used to be — which describes the mesh's nervous system as a port
of something that did a fraction of this. It now says what the bus is: a
role addressable without knowing its holder, the mesh's own state, work
that queues until somebody can do it, and permissions derived from what a
module declared. Conditions, observation and a person's client land there
too as they are built.

Glossary gains `bus` and `the deprecated broker`, with a note on why not to
say "compatibility broker" or name it after a protocol — the second invites
exactly the backwards framing this commit removes.

00-META/glossary.md

@@ -31,8 +31,22 @@ another — and a mesh you cannot name precisely is a mesh two people describe d
 - **store** — the one postgres server. It holds the controller's own context databases
   (`inventory`, `identity`, `licences` — a context owns its store, [ADR 0008](../02-DECISIONS/0008-a-context-owns-its-store.md))
   and every module's own database. One server, many databases — never one shared "mesh database".
-- **broker** — the one lavinmq message bus. It carries the mesh bus on the `/` vhost and a vhost per
-  consumer that requires `amqp`.
+- **bus** — the mesh's own nervous system: NATS, one per mesh, carrying every link the mesh has —
+  control, declarations, builds, events, tool calls
+  ([ADR 0106](../02-DECISIONS/0106-the-bus-is-nats.md)). A module reaches it by requiring
+  `mesh-bus` ([ADR 0120](../02-DECISIONS/0120-the-mesh-bus-is-required-not-ambient.md)); one that
+  does not require it has no account on it. Held by the `mesh-broker` seat, which is named after
+  the *role* rather than the server, so the server can change without the seat doing so.
+- **the deprecated broker** — the lavinmq module. It was the mesh's bus and is not any more. It
+  keeps running as an **ordinary provider** of the `amqp` provision, for modules that need a
+  message broker of their own the way something needs a database
+  ([ADR 0119](../02-DECISIONS/0119-amqp-is-a-provision-not-the-bus.md)) — no seat, not foundation,
+  never raised at genesis, and a mesh that never installs it is complete.
+
+  Say *the deprecated broker*, not "the compatibility broker" (it serves the mesh's own modules,
+  not only the predecessor's) and not "the AMQP broker" (naming it after a protocol invites
+  describing the bus by contrast with it, which is backwards: the bus is the mesh's nervous
+  system and this is a module).
 
 ## What the mesh stores and serves