# MountedStory

Live Storybook mount and its explicit asynchronous disposer.

## Signatures

```ts
export interface MountedStory {
    readonly canvas: HTMLDivElement;
    readonly dispose: () => Promise<void>;
}
```

## Why

Stories need access to the actual canvas for assertions and deterministic
teardown of a long-lived reactive render.

## Ownership and lifetime

The mount owns its private Scope and render fiber. `dispose` interrupts the
fiber and closes the Scope exactly once; callers own appending/removing the
returned canvas. If the canvas is connected, disposal does not disconnect the
removal observer; removing the canvas is the observer's cleanup boundary.

## Property: canvas

Detached div containing the story's real rendered DOM.

## Property: dispose

Idempotently closes rendering; remove a connected canvas to release its observer.