resolveStripRoot walks from host up to <mat-tab-header> and
locates .mat-mdc-tab-label-container via any rendered
.mat-mdc-tab descendant — Material's IO-friendly scroll
container.
resolveTabButton indexes positionally; Material owns the DOM
and cngx handle ids never reach the button elements. Index
correlates against presenter.tabs() registration order.
Wire it via the directive's
CNGX_TAB_OVERFLOW_DOM_ADAPTER_FACTORY provider: