Land feature 57's SDK work on its release branch

Providers, the state bus, templates and the environment collection that the
feature's modules build on (feature 57, config and provisioning).

README.md

@@ -20,7 +20,13 @@ Not the manifest schema (the control plane owns and parses that, in Go). The sha
 contains — the contract both a provider and a consumer conform to), and the tool and event types.
 These change rarely and deliberately; when one does, a rebuild of everything is *correct*.
 
-### `provisioner` — the reconcile harness every provider shares
+### `provider-loop` — the reconcile harness every provider on the grant files shares
+Called `provisioner` until design 57 (novox/hq issue 678); that word is mesh-provisioner's now. The old path and
+names (`/provisioner`, `runProvisioner`, `provisionerTools`) stay aliases until the providers importing them move to
+the Go helper that answers consumers over the bus (`go/provider`, design 57 B2 and B3) and this loop retires with the
+grant files. Its events and tools keep their names (`provisioner.failing`, `provisioner_retirement`, …): the
+controller and the operator read them.
+
 The loop is identical for postgres, redis, minio and umami: watch the grants directory, for each
 requested grant call the provider's adapter, write the sealed credential, handle withdrawal, and
 keep converging (`watch`). That loop lives here. A **module provides only the adapter** — "create
@@ -146,12 +152,12 @@ import { UmamiClient } from "../client.js"; // the client lives in the module, n
 registerModuleTools("umami", (env) => getUmamiTools(new UmamiClient(env.UMAMI_URL)));
 ```
 
-A provider's provisioner:
+A provider's loop:
 
 ```ts
-import { runProvisioner, Grant, Credential } from "@novox/mesh-sdk/provisioner";
+import { runProviderLoop, Grant, Credential } from "@novox/mesh-sdk/provider-loop";
 
-runProvisioner("analytics", {
+runProviderLoop("analytics", {
   async create(grant: Grant): Promise<Credential> { /* create a umami site, return the grant */ },
   async remove(grant: Grant): Promise<void> { /* delete the site */ },
 });