Mantine's Tabs keeps inactive panels mounted by default. On Mantine 9 with
React 19 that uses <Activity>, which preserves state and unmounts effects but
still builds the entire subtree - so a two-tab widget pays for both while
showing one.
health-monitoring both the system and the cluster monitoring view were built
media-missing both tabs built their full card list, each card with a
poster and a blurred backdrop
Two other Tabs users are deliberately left mounted: custom-api panels can hold
user component state, and the widget edit modal would reset half-filled forms.
media-missing also rendered every card into a scrolling tile with no lazy
loading, the same shape as media-releases. Its card height is fixed per density,
so contain-intrinsic-size is exact rather than a guess.
calendar fell back to https://placehold.co/400x400 when a poster failed to
load, so a self-hosted dashboard made a third-party request - once per failing
event - to draw a grey square, and showed nothing at all on a host without
internet access. Same grey square, inline.
The rss feed handler logged the whole serialised feed entry through a raw
console.debug, which no log level could suppress, and reported a match count
that was really the regex capture-group count.
Adds scripts/benchmarks/widget-inventory.mjs and docs/perf/WIDGET-AUDIT.md, a
verdict for all 50 widgets.
Thomas Camlong
ec79a15023