Both branches changed the seat set from the same starting point, so every number
collided and every `mesh-*` name existed twice. The trunk's numbers and names win:
this branch's records became 0129/0130 and its migrations 0037/0038, and the
hardcoded rename map gave way to the trunk's `seat_alias` table — a rename is a
row now (ADR 0122), not a recompile.
Three of my checks were wrong and the merge is what showed it:
A seat with an empty protocol is a marker, not an incomplete declaration. Most
node-scoped seats are markers — which module is this machine's packet filter —
and refusing one refused most of the set, the showcase module included. A
mistyped field name is already refused by the parser, so an empty protocol was
written as one deliberately.
A claim on a seat this manifest does not declare is not the parser's to judge. A
module may hold a seat another module declared; that is the whole reason ADR 0126
has callers name the seat and not its provider. Whether the seat exists is a fact
about the catalogue, so the refusal is at registration, where every declaration
is in view.
And a seat may share a name with the provision it delivers. `git`, the npm
registry and the artifact store still do, because renaming a delivering seat
cascades to every consumer requiring it, with a window where a holder stops
resolving mid-flight. The trunk deferred exactly those three on purpose.
Full suite green against a real NATS and store.
The rollout moves every node at once, so there is nothing to inspect afterwards and no
half to roll back — either the mesh was ready or it was not. That makes the readiness
question the valuable half: it costs nothing, it can be asked of a mesh that is serving as
many times as you like, and every answer is a thing somebody can go and fix.
It reads from records and dials once. Is a bus answering, does a machine hold the seat, has
that machine been sent the composed user list, does every machine have a credential for the
new bus, does every module that speaks. Each missing thing names its own next step, because
"not ready" that cannot be acted on is not an answer — and this is read at the point where
the next step is irreversible.
**A machine with no credential is the one that must stop it.** It keeps running and cannot
come back, and afterwards there is no bus to tell it anything over, so the remedy has to
happen first. The message says so.
A module that never reaches the bus is not counted as missing a credential. A third of the
catalogue never speaks, and listing those would bury the ones that matter.
`rollout --confirm` refuses and says why: the move is not being written before its check has
been run against a real mesh. And the plan it prints says the old broker stays — it remains
an ordinary provider of `amqp` for whatever else uses it, which on this installation is a
whole automation layer that has nothing to do with the mesh. This move is not its retirement,
and that is why it is survivable: what breaks if it goes wrong is the mesh's ability to
change things, not the services its modules serve.
jschoubben