The desktop CSP listed only known embed hosts in frame-src, so every
room widget that is not one of them (Jitsi, Etherpad, Grafana, bots)
showed a blank frame; the web deploy allows https: frames (#205).
Match it. Widget frames are sandboxed by cinny and same-origin widget
URLs are refused (isWidgetUrlSafe), so this does not widen what a
widget can do to the app.
Fixes#33
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017PCb59uY3UKqDqt7B6hzd5