Merge branch 'main' into the Android head

Main grew the screens the host-management plan called for — hosts, pins, snippets, logs,
import, teams — plus the ObjectStore and Import projects behind two of them, and moved
WindowsDeviceKeyStore into the desktop head's Platform folder.

Five of those view models landed in a directory this branch had already moved, so they
join the rest in DodoSSH.Client.Shell: git spotted the rename and put them there, and the
namespaces followed. Shell picks up ObjectStore and Import as a result, which the Android
head then gets transitively and will use neither of at first — scoped storage means there
is no ~/.ssh/config to import, and file transfer is out of its first scope.

Desktop suites green at 155 and 64.

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

@@ -19,7 +19,7 @@
 
   <StackPanel Spacing="12">
 
-    <TextBlock Classes="heading" Text="Unlock your vault" />
+    <TextBlock Classes="heading" Text="Unlock your keychain" />
     <TextBlock Text="{Binding AccountName}" Foreground="{StaticResource Info}" />
 
     <!--
@@ -33,7 +33,7 @@
       exists for. A single-line TextBox does not handle Enter itself, so nothing is being fought over.
     -->
     <TextBox x:Name="UnlockPassphrase" Text="{Binding Passphrase}"
-             PlaceholderText="vault passphrase" PasswordChar="•">
+             PlaceholderText="keychain passphrase" PasswordChar="•">
       <TextBox.KeyBindings>
         <KeyBinding Gesture="Enter" Command="{Binding UnlockCommand}" />
       </TextBox.KeyBindings>
@@ -52,7 +52,7 @@
               Command="{Binding UnlockWithDeviceCommand}"
               IsEnabled="{Binding !IsBusy}"
               IsVisible="{Binding CanUnlockWithDevice}"
-              ToolTip.Tip="Opens the vault with this machine's device key. Windows will ask you to confirm." />
+              ToolTip.Tip="Opens the keychain with this machine's device key. Windows will ask you to confirm." />
     </StackPanel>
 
     <TextBlock Classes="hint" Text="{Binding StatusMessage}" TextWrapping="Wrap" />
@@ -73,7 +73,7 @@
         <TextBlock Text="{Binding LiveSessionSummary}" Foreground="{StaticResource Info}"
                    FontWeight="SemiBold" TextWrapping="Wrap" />
         <TextBlock Classes="hint" FontSize="11" TextWrapping="Wrap"
-                   Text="Locking closes the vault, not your terminals: a job you started keeps running, and its output is waiting behind this screen. It also means this machine still holds an open, authenticated channel to those hosts — locked describes the vault, not the connections. Quit DodoSSH to end them." />
+                   Text="Locking closes the keychain, not your terminals: a job you started keeps running, and its output is waiting behind this screen. It also means this machine still holds an open, authenticated channel to those hosts — locked describes the keychain, not the connections. Quit DodoSSH to end them." />
       </StackPanel>
     </Border>
 
@@ -88,7 +88,7 @@
 
     <StackPanel Spacing="6">
       <TextBlock Classes="hint" FontSize="11" TextWrapping="Wrap"
-                 Text="Forgotten your passphrase? Nothing can recover it — not even whoever runs the server. What you can do is reset this machine and sign in again; the vault is on the server and comes back." />
+                 Text="Forgotten your passphrase? Nothing can recover it — not even whoever runs the server. What you can do is reset this machine and sign in again; the keychain is on the server and comes back." />
       <Button Classes="ghost" Content="RESET THIS MACHINE"
               Command="{Binding SignOutCommand}" HorizontalAlignment="Left" />
     </StackPanel>