ADR 0113 and to-be 27: address the review of the vault rework

Two decisions taken with the author:
- Genesis delivers and the vault adopts. The vault cannot run first — it is built on the runtime base
  the installation makes after the store, broker and controller, and it learns its work over the bus.
  Genesis generates the foundation's first shared secrets, seals them to the operator key, and
  delivers them to the vault through the path an operator's value takes; from then on the vault holds
  and rotates them. This answers ADR 0085's own reason for rejecting vault-only minting, which 0113
  now names instead of stepping around.
- Rotation re-confirms on every pass. An applier repeats its confirmation until acknowledged, so a lost
  message costs one pass; an applier that stops after applying locks readers out until its supervised
  restart, and that window is stated and shown, not claimed away.

Fixes:
- Scope: a shared secret is made by the vault; a private key (node sealing keys, the operator's key,
  the certificate authority) is made where it is used. The inventory adds the makers the first version
  missed: node and builder broker passwords, and enrolment tokens.
- Broker accounts are created by the broker's provisioner, not the controller, so the controller never
  holds their plaintext; mesh-broker delivers amqp again — one broker per mesh — and only mesh-store
  delivers nothing.
- secret is a reserved provision: only the mesh-vault holder may provide it, and no pin routes around it.
- A secret's contract says whether a recipient applies it or reads it at start; appliers are never
  restarted for it, init-only secrets are applied, and confirmation is to-be 13's standard.
- Operator secrets are one rule everywhere: a secret requirement answered by the vault (0112 no longer
  says otherwise). A data provider's adapter may return fields; the data-return check names a lab consumer.
- 'Holder' now means a seat's holder only; a secret has recipients.

03-DESIGN/01-to-be/23-choosing-a-provider.md

@@ -57,9 +57,10 @@ consumer's own machine does not take over for that consumer. That is not picking
 once, mesh-wide, by assigning the holder, rather than once per consumer by naming it
 ([ADR 0110](../../02-DECISIONS/0110-a-seat-is-a-module-assignment-from-a-closed-set.md),
 [26 — The seats](26-the-seats.md)). A named provider still wins over the seat, because a consumer
-coupled to particular contents has said so. Only provisions the design makes one-per-mesh are
-delivered by a seat: the artifact store, a package registry, git and the vault. A database is not.
-Node-local stores, served by co-location, are the rule above.
+coupled to particular contents has said so, except for `secret`, which only the vault may provide.
+Only provisions the design makes one-per-mesh are delivered by a seat: the broker, the artifact store,
+a package registry, git and the vault. A database is not. Node-local stores, served by co-location,
+are the rule above.
 
 **Ambiguity is refused, never resolved by picking.** If several providers of a kind exist, none is
 named, none is co-located, and no seat delivers it, the requirement is unsatisfiable and is refused