Document the bundled OpenRouter configuration

README.md

@@ -26,6 +26,8 @@ source-relative prompt content, supplies an inline input, and prepares through
 a scoped view. The example also demonstrates collection inventories and
 namespace-filtered discovery, without contacting a provider or requiring
 credentials.
+The example disables the bundled OpenRouter configuration to keep its
+inventories limited to its own offline fixtures.
 The [consumer guide](docs/consumers/pkg-promptkit.md) also shows a local backend,
 ordered file/embedded sources, programmatic mappings, and how to replace an
 engine when source files change. Applications adapting the prior keyed