ios: reorderable tab bar with more tabs, debug log export, AirPlay picker, more room above seeker

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

ios/Stemify/UI/RootView.swift

@@ -9,7 +9,7 @@ struct RootView: View {
         let s = g.settings
         let p = Palette.of(s.theme, s.accent)
         TabView(selection: Binding(get: { ui.tab }, set: { ui.selectTab($0) })) {
-            ForEach(Tab.allCases, id: \.self) { t in
+            ForEach(Tab.layout(s.tabLayout), id: \.self) { t in
                 NavigationStack(path: ui.path(t)) {
                     root(t).miniPlayerRoom()
                         .navigationDestination(for: Route.self) { destination($0).miniPlayerRoom() }
@@ -20,6 +20,7 @@ struct RootView: View {
             }
         }
         .modifier(GlassMiniPlayerHost())
+        .onChange(of: s.tabLayout) { _, _ in ui.ensureValidTab() }
         .sheet(isPresented: Binding(get: { ui.nowPlayingOpen }, set: { ui.nowPlayingOpen = $0 })) {
             NowPlayingScreen()
                 .overlayHost(ui.overlays, level: 1)
@@ -41,6 +42,10 @@ struct RootView: View {
     @ViewBuilder private func root(_ t: Tab) -> some View {
         switch t {
         case .Library: LibraryHome()
+        case .Songs: SongsScreen()
+        case .Albums: AlbumsScreen()
+        case .Artists: ArtistsScreen()
+        case .Genres: GenresScreen()
         case .Playlists: PlaylistsScreen()
         case .Search: SearchScreen()
         case .Downloads: DownloadsScreen()
@@ -54,6 +59,10 @@ struct RootView: View {
         case .Albums: AlbumsScreen()
         case .Songs: SongsScreen()
         case .Playlists: PlaylistsScreen()
+        case .Genres: GenresScreen()
+        case .Downloads: DownloadsScreen()
+        case .TabBar: TabBarScreen()
+        case .GenrePage(let g): GenreScreen(genre: g)
         case .Eq: EqScreen()
         case .EqFilters(let id): EqFiltersScreen(profileId: id)
         case .EqFilterPage(let id, let f): EqFilterPage(profileId: id, filterId: f)