Refactor useGridLayout from RefObject to callback-ref API so the
ResizeObserver reattaches when the grid container remounts after
focus-mode toggle. Fixes tiles rendering at stale fullscreen dimensions
on 4:3 monitors.
Also clamp focus-mode participant strip height (max-h-[20vh] min-h-[80px])
to prevent it from crowding the focused stream on short viewports.
Replace hardcoded Tailwind grid-cols breakpoints with a container-aware
layout algorithm that uses ResizeObserver to recompute optimal tile
arrangement. Maximizes tile area while maintaining 16:9 aspect ratio,
automatically adapting when VoiceChatPanel opens/closes, window resizes,
or fullscreen is toggled.
Jannis Braun