Select width, style and weight capabilities before filtering FontFaceSet
queries by text and unicodeRange. Share the matching path for check/load,
including CSS calculations and descriptor ranges, so unrelated unloaded
or broken sources do not affect a query.
Publish each Document's CSS/manual FontFaceSet order independently from
stable resource slots. Preserve manual overrides, re-addition priority
and different orders for shared faces across Documents.
Cover the matching and actual DOM geometry regressions with generated
narrow/wide fonts and a shared Chromium/Moli CDP oracle.