Joining a space from the room flow. (#4563)

* Add the More menu to SpaceScreen.

And a simple way to leave a space for testing.

* Start a space flow when accepting a space invite from the room flow.

* Minimise the tab bar on iOS 26 when scrolling down.

* Enable spaces by default!

ElementX/Sources/Application/Navigation/NavigationTabCoordinator.swift

@@ -307,6 +307,7 @@ private struct NavigationTabCoordinatorView<Tag: Hashable>: View {
                     .toolbar(module.details.barVisibility(in: horizontalSizeClass), for: .tabBar)
             }
         }
+        .backportTabBarMinimizeBehaviorOnScrollDown()
         .introspect(.tabView, on: .supportedVersions, customize: configureAppearance)
         .sheet(item: $navigationTabCoordinator.sheetModule) { module in
             module.coordinator?.toPresentable()