Fix Office 2016 visibility with ScrollViewer, bump to v1.21

Version page now scrollable to fit all 4 Office versions.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Pages/VersionPage.xaml

@@ -15,7 +15,8 @@
                        Foreground="{StaticResource TextSecondaryBrush}" Margin="0,4,0,0"/>
         </StackPanel>
 
-        <StackPanel Grid.Row="1" VerticalAlignment="Top">
+        <ScrollViewer Grid.Row="1" VerticalScrollBarVisibility="Auto" HorizontalScrollBarVisibility="Disabled">
+        <StackPanel VerticalAlignment="Top">
             <RadioButton x:Name="Rb2024" Style="{StaticResource CardRadioButton}"
                          GroupName="Version" IsChecked="True" Margin="0,0,0,10">
                 <StackPanel Margin="8,2">
@@ -52,5 +53,6 @@
                 </StackPanel>
             </RadioButton>
         </StackPanel>
+        </ScrollViewer>
     </Grid>
 </Page>