Chromium >=121 wraps a <details>'s content in a generated ::details-content
box with content-visibility:hidden while closed. The SSR app-shell ships
closed (no JS) and hides its summary toggle at lg+, so on desktop the rail+page
were invisible and the flex-lg-row layout collapsed to a vertical stack.
Add '.app-shell::details-content { display: contents }' inside the lg+ media
query: dissolving the wrapper box reveals the content regardless of open state
and restores rail/page as direct flex children of .app-shell. Browsers without
::details-content support drop the invalid selector and fall back to the legacy
force-show. Mobile (<lg) and nested NavRailSection disclosures unaffected.
Bump 0.2.0 -> 0.2.1.
Joseph Doherty