Give the window its v5b chrome and each session surface its own shell

src/DodoSSH.Client.App/Views/NavRail.axaml.cs

@@ -1,9 +1,85 @@
 using Avalonia.Controls;
+using Avalonia.Controls.Primitives;
+using Avalonia.Interactivity;
+using DodoSSH.Client.Shell.ViewModels;
 
 namespace DodoSSH.Client.App.Views;
 
-/// <summary>The five destinations down the left edge of the unlocked window.</summary>
+/// <summary>The window's destinations, down the left edge — the switcher, the six rail rows and the user chip.</summary>
 internal sealed partial class NavRail : UserControl
 {
     public NavRail() => InitializeComponent();
+
+    /// <summary>Opens the user popover.</summary>
+    /// <remarks>
+    /// A handler rather than relying on the click that opening a <c>Flyout</c> answers to on its own: a
+    /// named method is a thing a test can call directly, where an implicit open is not.
+    /// </remarks>
+    private void OnUserChipPressed(object? sender, RoutedEventArgs e)
+    {
+        if (sender is Control chip)
+        {
+            FlyoutBase.ShowAttachedFlyout(chip);
+        }
+    }
+
+    /// <summary>Hides the popover, whatever handler is about to navigate.</summary>
+    private void ClosePopover()
+    {
+        if (this.FindControl<Button>("UserChip") is { } chip)
+        {
+            FlyoutBase.GetAttachedFlyout(chip)?.Hide();
+        }
+    }
+
+    /// <summary>Leaves for the vaults screen with the new-vault form open, shutting the popover behind it.</summary>
+    /// <remarks>
+    /// The popover is closed first: the command navigates, and a popup left open would be hanging over a
+    /// screen it has nothing to do with. A <c>Flyout</c> does not close on its own when something inside it
+    /// is pressed — which is what the vault switches above it want, and not what this wants.
+    /// </remarks>
+    private void OnPopoverNewVaultPressed(object? sender, RoutedEventArgs e)
+    {
+        ClosePopover();
+
+        if (DataContext is MainWindowViewModel shell)
+        {
+            shell.ShowNewVaultCommand.Execute(null);
+        }
+    }
+
+    /// <summary>Settings and Preferences both land here — see the remark in the markup.</summary>
+    private void OnPopoverPreferencesPressed(object? sender, RoutedEventArgs e)
+    {
+        ClosePopover();
+
+        if (DataContext is MainWindowViewModel shell)
+        {
+            shell.ShowScreenCommand.Execute(ShellScreen.Preferences);
+        }
+    }
+
+    private void OnPopoverVaultsPressed(object? sender, RoutedEventArgs e)
+    {
+        ClosePopover();
+
+        if (DataContext is MainWindowViewModel shell)
+        {
+            shell.ShowScreenCommand.Execute(ShellScreen.Vaults);
+        }
+    }
+
+    /// <summary>
+    /// Starts a sign-out, through Preferences so the confirmation card has somewhere to be seen — see
+    /// <see cref="MainWindowViewModel.SignOutFromPopover"/>.
+    /// </summary>
+    private void OnPopoverLogoutPressed(object? sender, RoutedEventArgs e)
+    {
+        ClosePopover();
+
+        if (DataContext is MainWindowViewModel shell)
+        {
+            shell.SignOutFromPopoverCommand.Execute(null);
+        }
+    }
 }