Move admin screens (users/groups/roles/oauth2-clients) into a drop-in example plugin; add the ctx.system capability surface

src/plugin-host/plugin-api.ts

@@ -11,8 +11,20 @@ export type { PageChrome } from "../ui/chrome.ts";
 export type { NavNode } from "../ui/nav.ts";
 export { can, check, GuardError, requireSession } from "../auth/guards.ts";
 export { parseListQuery } from "../ui/list-query.ts";
+export { paginate } from "../ui/paginate.ts";
+export type { PageModel } from "../ui/paginate.ts";
 export { readFormBody } from "../http/body.ts";
 export { CSRF_FIELD } from "../auth/csrf.ts";
+// System capabilities for a privileged/system plugin (ctx.system) — the Ory admin clients + the
+// instant-revoke hook. Undefined unless the host wired them; the built-in admin plugin is the
+// reference consumer. The Ory client types + their error classes are re-exported so a system
+// plugin can type against them and `instanceof`-match their errors. See README → System capabilities.
+export type { SystemCapabilities } from "./system.ts";
+export type { Identity, KratosAdmin, RecoveryCode } from "../auth/kratos-admin.ts";
+export type { ExpandTree, KetoClient, RelationQuery, RelationTuple, SubjectSet } from "../auth/keto-client.ts";
+export type { HydraAdmin, OAuth2Client } from "../auth/hydra-admin.ts";
+export { KratosError } from "../auth/kratos-public.ts";
+export { HydraError } from "../auth/hydra-admin.ts";
 // Sanitise an untrusted URL (upstream/user data) before rendering it in an href/src — partials
 // escape text but not URL schemes, so a `javascript:`/`data:` URL would be live XSS (see docs).
 export { safeUrl } from "../http/safe-url.ts";