- `lotusHostControls=1`: body.lotus-host-controls hides EC's footer
(position absolute + visibility hidden, still in the DOM so a host on an
engine without Capability Delegation can click its screenshare button).
- With lotusTheme/lotusTransparent, `:root` color-scheme follows the
theme, so the transparent frame gets no opaque backdrop.
Together these replace the CSS the host injected into this frame.
Also fixes unreadable tile name tags in the light theme: the Lotus
near-black canvas override now applies to dark themes only (it sat behind
light-theme dark text).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PPmy3tPq869XDW4njjVaKA