effectTransition property
How chrome that appears or disappears across a transition animates — a back button on the first push off the root, an actions capsule on a route whose destination has none.
Defaults to GlassEffectTransition.materialize, mirroring iOS 26. GlassEffectTransition.identity restores the single switch at the transition midpoint, which is what reduce motion selects too.
Set on the shell rather than per screen because the choreography spans two routes: with a knob on each bar, a push between routes that disagree would have no answer for which one wins.
Implementation
final GlassEffectTransition effectTransition;