pub fn adopt_initial_window(root: RNode, scope: Scope)Expand description
Adopt the app’s first window into the registry, so it is an ordinary primary window rather than a privileged one (docs/windows.md close policy).
Called once at boot with the root container the backend handed back. scope owns the root
content, so closing this window disposes exactly its tree and nothing else, which is
why the caller builds that content in a child of the root scope rather than in the root
scope itself. State an app wants to outlive its windows still does: Signal::global lives
on the root scope, above this one.