Give the application a settings area built from what really exists

src/DodoSSH.Client.App/Views/MainWindow.axaml

@@ -91,12 +91,13 @@
 
   <Grid RowDefinitions="Auto,*,Auto,Auto">
 
-    <views:TitleBar Grid.Row="0" />
+    <views:TitleBar Grid.Row="0" IsVisible="{Binding !IsSettingsMode}" />
 
     <Panel Grid.Row="1">
 
       <!-- The unlocked application. -->
-      <Grid ColumnDefinitions="Auto,*" IsVisible="{Binding IsUnlocked}">
+      <Grid ColumnDefinitions="Auto,*" IsVisible="{Binding IsUnlocked}"
+            IsEnabled="{Binding !IsSettingsMode}">
 
         <!--
           The window's own furniture, at 255 pixels — see NavRail.axaml's own v5b remark. It no longer sits
@@ -176,13 +177,19 @@
               by a toggle inside the screen — see ShowFiles, and the rail's own switcher segment that
               calls it now; see NavRail.axaml.
 
-              Deliberately not given the session shell above: a bucket is not a host, has no terminal tab
+              Deliberately not given the full session shell above: a bucket is not a host, has no terminal tab
               to be the other end of a cross-surface button, and pins nothing the sidebar's QUICK ACCESS
-              could show. Wave B's own scope is the terminal and SFTP surfaces; S3 stays the plain screen it
-              already was, and this is the recorded reason rather than an oversight.
+              could show — so no tab row, no host header, no status bar and no sidebar. Wave B's own scope
+              was the terminal and SFTP surfaces and left this plain; v5c-3 gives it the session shell's own
+              LOOK without its machinery — a 26px padded column and the same bordered, radius-12 container —
+              since design-notes/v5c-fidelity-notes.md calls for the fidelity pass here too, and there is
+              nothing this screen does that needs the parts still withheld.
             -->
             <Panel IsVisible="{Binding IsBucketsScreen}">
-              <views:TransfersScreen DataContext="{Binding Transfers}" />
+              <Border Margin="26" BorderBrush="{StaticResource Border}" BorderThickness="1" CornerRadius="12"
+                      ClipToBounds="True">
+                <views:TransfersScreen DataContext="{Binding Transfers}" />
+              </Border>
             </Panel>
 
             <!-- ============ KEYCHAIN ============ -->
@@ -217,30 +224,21 @@
               <views:LogsScreen x:Name="LogsPane" DataContext="{Binding LogsScreen}" />
             </Panel>
 
-            <!-- ============ VAULTS ============ -->
             <!--
-              Wrapped, for the reason the keychain and transfers screens are: the visibility is the shell's
-              business and the data context is the vaults view model, and both on one element would resolve
-              IsVaultsScreen against a type that does not have it.
+              v5c-2: the VAULTS panel that used to live here is gone. ShellScreen.Vaults now only ever shows
+              through settings mode's own SettingsVaultsPage — see MainWindowViewModel.ShowScreen, which
+              redirects it into EnterSettings before Screen is ever set — so IsVaultsScreen being true also
+              means IsSettingsMode is true, and this whole page-area Panel (bound to !IsSettingsMode, above)
+              is already hidden behind SettingsView by then. A Panel here would never have been drawn.
 
-              Bound to Vaults, which is the vaults themselves and the people in them — not to Vault, which
-              is one vault's contents and is what the keychain and hosts screens above draw.
+              v5c-3: IMPORT left this Panel the same way, and for the same reason. Import.dc.html draws the
+              importer inside the settings chrome — SettingsNav lit on Preferences, a "Back to preferences"
+              titlebar rather than the ordinary rail and titlebar this Panel belongs to — so ImportScreen now
+              lives in SettingsView.axaml behind MainWindowViewModel.IsImportOpen, beside the seven settings
+              pages rather than among the screens here. See ShowScreen's own translation of
+              ShellScreen.Import for what still reaches it: the Preferences page's own "OPEN IMPORTER" row,
+              and anything else that names the same destination.
             -->
-            <Panel IsVisible="{Binding IsVaultsScreen}">
-              <views:VaultsScreen DataContext="{Binding Vaults}" />
-            </Panel>
-
-            <!-- ============ PREFERENCES ============ -->
-            <views:PreferencesScreen IsVisible="{Binding IsPreferencesScreen}" />
-
-            <!-- ============ IMPORT ============ -->
-            <!--
-              Reached from preferences rather than from the rail; see ShellScreen.Import. Wrapped, like
-              the others whose data context is their own view model.
-            -->
-            <Panel IsVisible="{Binding IsImportScreen}">
-              <views:ImportScreen x:Name="ImportPane" DataContext="{Binding ImportScreen}" />
-            </Panel>
 
           </Panel>
 
@@ -319,6 +317,22 @@
         </Panel>
       </Grid>
 
+      <!--
+        v5c: the settings mode, which replaces the titlebar above and everything in this Panel below it with
+        its own — see SettingsView.axaml and TitleBar's own IsVisible next to it in this file. Later in the
+        Panel than the unlocked Grid, on the same reasoning the setup Border below gives for its own
+        position: Avalonia z-order draws a later sibling over an earlier one, and SettingsView's own
+        Background is opaque, so it covers the rail and the page area completely rather than needing them
+        hidden out from under it. The unlocked Grid keeps IsEnabled bound to the negation above so a Tab
+        press cannot walk keyboard focus into a control this mode has covered.
+
+        Earlier than the palette and the host-key decision, both further down this same Panel, so either can
+        still interrupt settings mode exactly as it already interrupts every other screen — a host key that
+        changes while the sync loop is running does not stop being worth answering because the window
+        happens to be showing Settings.
+      -->
+      <views:SettingsView IsVisible="{Binding IsSettingsMode}" />
+
       <!--
         Setup and unlock. Later in the Panel, so it is above the application content in Avalonia's z-order —
         which covers Avalonia-drawn content and nothing else. The terminal is collapsed rather than covered;
@@ -476,11 +490,18 @@
       no DataContext yields UnsetValue, IsVisible falls back to true, and the previewer would show a banner
       announcing an update that does not exist.
     -->
-    <views:UpdateBanner Grid.Row="2"
-                        DataContext="{Binding Updates}"
-                        IsVisible="{Binding IsBannerShowing, FallbackValue=False}" />
+    <!--
+      v5c: wrapped rather than given a third condition of its own — UpdateBanner sets its own DataContext to
+      UpdateViewModel on this same element, so a binding against IsSettingsMode has to live on an ancestor
+      whose context is still the shell. The design's settings titlebar has no room for this strip; hiding it
+      here rather than teaching the banner about a mode it otherwise has no reason to know about.
+    -->
+    <Panel Grid.Row="2" IsVisible="{Binding !IsSettingsMode}">
+      <views:UpdateBanner DataContext="{Binding Updates}"
+                          IsVisible="{Binding IsBannerShowing, FallbackValue=False}" />
+    </Panel>
 
-    <views:StatusBar Grid.Row="3" />
+    <views:StatusBar Grid.Row="3" IsVisible="{Binding !IsSettingsMode}" />
 
   </Grid>