When the panel window was reused, it was not re-initialized. That includes the panel size request. If the last panel size was matching a different display size (including orientation), the newly shown panel would re-use that size instead of respecting the newly requested size.
A redesign of popover was needed: it can no longer query the application state directly due to current state being its own actor, so instead the popover gets a dedicated copy of the relevant state.
I'm not entirely happy with the extra complexity of having an extra actor just for 1 string, but at least the duplication between C and Rust and mutual calls have been reduced.
