localStorage-backed set of serials at key 'imaging-expanded'. On
DOMContentLoaded, walk each .imaging-card; if its data-serial is in
the set, set card.open=true. On every <details> toggle, update the
set. Refresh no longer collapses the tile the operator was looking
at.
Per-browser state (localStorage), no server round-trip.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
036090348c