refactor: consolidate agent/editor plugins under integrations/ (#5491)

Co-authored-by: Claude <noreply@anthropic.com>

integrations/openclaw/backend/index.ts

@@ -0,0 +1,12 @@
+export { PlatformBackend } from "./platform.ts";
+export {
+  type Backend,
+  type AddOptions,
+  type SearchOptions,
+  type ListOptions,
+  type DeleteOptions,
+  type EntityIds,
+  AuthError,
+  NotFoundError,
+  APIError,
+} from "./base.ts";