The mobile drawer is a modal dialog, but the Tab trap was bound to .root only,
while the backdrop button renders as a sibling OUTSIDE .root — so Tab from the
backdrop (or any out-of-root node) could escape the modal. Move the trap to the
host keydown listener (keydown is composed, so it catches the backdrop too) and
include the backdrop in the focusable cycle; keep initial focus on the first
real control. Adds a regression test for backdrop/outside-root Tab containment.
The UMD bundle inlines lit for a self-contained CDN <script>; inlining lit also
pulls in its runtime deps (@lit/reactive-element, lit-html, lit-element,
@lit-labs/ssr-dom-shim). tsdown flags that transitive bundling as 'unintended'
and promotes the warning to a fatal error under CI, breaking
@copilotkit/web-components:build (and every dependent). Declare all lit packages
in noExternal and set inlineOnly: false to mark the bundling intentional.
Shadow-DOM Lit element that renders the threads drawer: self-contained styles
with build-time token sync from react-core's theme, slot projection for custom
rows, license/upsell gating, filtering, and a mobile modal. View-state lives on
the element; domain state stays with the host. Multi-format build (ESM/CJS
externalize lit as a peer dep; UMD inlines lit so the CDN <script> path is
self-contained).
Benjamin Taylor