Graduate issues 067 and 068 to decisions and to-be designs

ADR 0084 (extends 0027) — a provision is served by a node-scoped provider the
consumer selects, defaulting to co-location; a module may instead carry a private
embedded instance that is not a provision. Design: 01-to-be/23-choosing-a-provider.

ADR 0085 (extends 0031) — a secret is a provision and the vault is the module that
provides it; a module's own local secret becomes an ordinary pair credential that
rotates through the existing machinery, while the controller's provisioning-credential
mint (0048) is unchanged. Design: 01-to-be/24-the-secrets-vault; doc 13 amended to
cross-link the non-pair secret.

Issues 067/068 marked resolved with amended-design set. ADR index regenerated;
records and index checks pass.

Claude-Session: https://claude.ai/code/session_01D6qtiYU3P9jk3pnAXyAFyx

02-DECISIONS/README.md

@@ -136,6 +136,8 @@ python3 00-META/checks/index.py            fail if stale
 - **0053** — [A scheduled step is a container run on a recurring schedule](0053-a-step-that-runs-on-a-schedule.md)
 - **0054** — [Model usage is a vendor-neutral record, produced by the adapter, at two grains](0054-model-usage-is-recorded-at-two-grains.md)
 - **0055** — [Model access is answered by a licence, or by a node that hosts the model](0055-model-access-is-answered-by-a-licence-or-a-node.md)
+- **0084** — [Which provider serves a consumer, when the mesh runs more than one](0084-which-provider-serves-a-consumer.md)
+- **0085** — [A secret is a provision, and the vault is the module that provides it](0085-a-secret-is-a-provision.md)
 
 ### How it is built