Interactive island contract¶

Tokimu-powered regions are optional guests inside an ordinary static page. The page owns durable knowledge; an island may add executable evidence after explicit activation.

Declarative boundary¶

An island root declares a semantic consumer name and an initial lifecycle state:

<section
  data-tokimu-island="asset-observation"
  data-state="idle"
>
  <!-- Static fallback content remains readable here. -->
</section>

Configuration is inert JSON owned by the page:

<script type="application/json" data-island-config>
  {
    "schema": 1,
    "fixture": "asset-observation-v1",
    "activation": "explicit",
    "maxBytes": 8388608
  }
</script>

The browser adapter passes this data to the registered consumer. It does not interpret importer, simulation, or presentation meaning.

Lifecycle¶

Each island has an independent controller and one of these visible states:

State	Meaning
`idle`	Static content is active and no interactive resources are owned.
`loading`	The registered consumer is starting under an abort signal.
`ready`	The consumer mounted and owns a bounded release callback.
`unsupported`	No compatible consumer is published for this build or browser.
`failed`	Startup failed and the static explanation remains available.
`unmounted`	Event, WASM, and renderer resources have been released.

Reset passes through unmounted before returning to idle. Navigation away from the page disposes every discovered island.

Loader boundary¶

An interactive bundle registers itself by semantic island name:

window.TokimuIslands.register("asset-observation", async (context) => {
  const consumer = await mountTokimuConsumer(context);
  return {
    release() {
      consumer.dispose();
    },
  };
});

The context contains only the island root, parsed configuration, and an AbortSignal. Independent islands do not share application state.

Failure contract¶

Missing or failed interactive code never removes the static fallback. State changes are exposed through textual status and the bubbling tokimu:island-state event. A consumer must report unsupported behavior rather than silently substituting browser-native import or rendering semantics.

This contract is exercised by the homepage asset-observation consumer. That island invokes Tokimu's Rust/WASM SVG inspection path after explicit activation; it does not establish a general browser-rendering guarantee.