Device health, one panel per rack

Sixty racks, one shared temperature scale, and only the panels you can see are live charts. Scroll the grid: panels mount as they approach the viewport and unmount as they leave, so the page stays light at any fleet size. RACK-27 is the one to worry about.

This grid is virtualized: trellis.virtualize: true mounts only the panels intersecting the viewport (plus one row of look-ahead). Every cell keeps its header and a fixed-height skeleton, so page height and scroll position never shift; a panel that scrolls out is destroyed with its view stashed, and scrolling back restores it, zoom window included. Above 64 panels this happens automatically (virtualize: 'auto'). The shared y scale is what makes the hot rack obvious, the traces paint on the canvas renderer (chart.renderer: 'canvas'), and mount animations default off above 16 panels. Trellis is a premium feature; without a license it renders with a trial watermark.