The suggestion list shares the prompt's shadow root

jolly-console is split along its concerns. The scrollback is its own element, jolly-console-log, with its own shadow root and styles. The suggestion list and the keyboard are reactive controllers, SuggestionController and KeyboardController, whose templates render into the jolly-console shadow root.

The list cannot be a child element with a shadow root. The prompt is a combobox that points at the list with aria-controls and at the highlighted option with aria-activedescendant. Both are IDREFs, and an IDREF does not resolve across a shadow boundary, so screen readers would lose the highlighted option. The scrollback has no such reference and can be encapsulated.

Considered Options

• A list element without a shadow root (createRenderRoot() returning the host). The IDREFs would resolve, but the element would depend on styles from its parent, which is a component in name only.
• Element reflection (ariaActiveDescendantElement). It crosses shadow roots, but browser support is not complete enough to rely on for the one assistive path the combobox has.

Consequences

List styles stay in Console.styles.ts. Controllers are tested under node --test with a stub host; rendering, focus and scrolling are covered by the Playwright suite.