requestFullscreen() on the voice container puts only its descendants in the
browser's top layer; overlays portaled to document.body were rendered outside
that layer and stayed invisible — most visibly the right-click context menu on
stream tiles and voice user panels.
Add usePortalContainer() hook returning document.fullscreenElement ?? document.body
and re-rendering on fullscreenchange. Migrate every overlay reachable during a
call: ContextMenuRenderer (desktop, submenu, mobile sheet), Tooltip,
ConfirmDialog, ConnectionInfoPopover, ScreenShareSettingsPopover, and
ScreenSharePicker (which previously rendered inline at App root).
federation.md — new undeliverable bucket subsection with three-way
classification table, Path A/B semantics, and wire backward-compat note.
voice.md — no_recipient row in failure-surface table.
websocket.md — DmCallUndeliverableReason union updated to include no_recipient.
dm-system.md — cross-reference to voice.md for no_recipient reason.
Jannis Braun