Add CancelCountdown feature and button

Added a CancelCountdown command to stop the countdown and reset the refresh button's accent state. Introduced a CancelCountdownButton in the UI, bound to the command, with conditional visibility and a tooltip for canceling auto-refresh.

Author: TheJoeFin

Simple Icon File Maker/Simple Icon File Maker/ViewModels/MainViewModel.cs

@@ -280,6 +280,13 @@ public void SizeCheckboxTapped()
         CheckIfRefreshIsNeeded();
     }
 
+    [RelayCommand]
+    public void CancelCountdown()
+    {
+        StopCountdown();
+        RefreshButtonIsAccent = false;
+    }
+
     [RelayCommand]
     public async Task RefreshPreviews()
     {

Simple Icon File Maker/Simple Icon File Maker/Views/MainPage.xaml

@@ -431,6 +431,18 @@
                         </MenuFlyout>
                     </Button.ContextFlyout>
                 </Button>
+                <Button
+                    x:Name="CancelCountdownButton"
+                    Height="32"
+                    MinWidth="32"
+                    Padding="8,0"
+                    HorizontalAlignment="Center"
+                    VerticalAlignment="Center"
+                    Command="{x:Bind ViewModel.CancelCountdownCommand}"
+                    ToolTipService.ToolTip="Cancel auto-refresh"
+                    Visibility="{x:Bind ViewModel.IsCountdownActive, Converter={StaticResource BoolVis}, Mode=OneWay}">
+                    <FontIcon FontSize="12" Glyph="&#xE711;" />
+                </Button>
                 <TextBlock
                     VerticalAlignment="Center"
                     Style="{StaticResource BodyStrongTextBlockStyle}"