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/SignOutCard.axaml

@@ -28,7 +28,7 @@
                TextWrapping="Wrap" />
 
     <TextBlock Classes="hint" FontSize="11" TextWrapping="Wrap"
-               Text="This deletes this machine's copy of the vault — the profile, the cached hosts, keys and passwords, and this machine's device key. Your vault is on the server and is not touched: signing in again brings it all back." />
+               Text="This deletes this machine's copy of the keychain — the profile, the cached hosts, keys and passwords, and this machine's device key. Your keychain is on the server and is not touched: signing in again brings it all back." />
 
     <Border Background="{StaticResource Panel}" BorderBrush="{StaticResource Border}"
             BorderThickness="1" CornerRadius="4" Padding="10,8"