Support bottom toolbar

[Luc1412]

unstable_headerRightItems and unstable_headerLeftItems allow to define toolbar items with placing in the top. iOS also supports placing items in the bottom toolbar. #3168 should also allow the search bar integration into the bottom bar. Not sure if it is in scope of Stack, but if so it can be pretty useful, especially with the rework of the toolbar in iOS 26.

Apple ref: https://developer.apple.com/documentation/SwiftUI/Toolbars

Example

SwiftUI Code:

struct ContentView: View {
    u/State private var searchText: String = ""
    
    var body: some View {
        NavigationStack {
            Text("Content")
                .searchable(text: $searchText)
                .toolbar {
                    ToolbarItem(placement: .bottomBar) {
                        Button {} label: { Label("New", systemImage: "plus") }
                    }
                    ToolbarSpacer(placement: .bottomBar)

                    
                    DefaultToolbarItem(kind: .search, placement: .bottomBar)

                    ToolbarSpacer(placement: .bottomBar)
                    

                    ToolbarItem(placement: .bottomBar) {
                        Button {} label: { Label("New", systemImage: "plus") }
                    }
                }
        }
    }
}

[kkafar]

Hey, we talked about this on one of the team meetings, but the idea didn't get traction back then. But I can clearly see the benefits of having that. I'm not sure though it's in the scope of this package.

I'll raise this topic on team meeting next week to see whether we'd be willing to proceed here.

Thanks for bringing up the idea!

[kkafar]

So following up here:

We'll do a PoC & see how this integrates, as it might be sensible to have this inside the lib to allow for full integration with system items etc. We assign this ticket a low prio, however.

[Luc1412]

Appreciate your efforts in this topic.