adopt focusgroup and its polyfill#35884

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marchbox wants to merge 25 commits intomicrosoft:masterfrom

marchbox:users/machi/focusgroup

Commits on Mar 23, 2026

adopt focusgroup for tree and tree-item
marchbox
committed

Commits on Mar 24, 2026

opt out items nested in a collapsed tree-item
marchbox
committed

Commits on Mar 26, 2026

Commits on Apr 4, 2026

use the polyfill package
marchbox
committed