chore(claude-do): [A3] Settings + Update-Check: OperationStatus für Skill-Inst

Vorgaben: `docs/superpowers/plans/2026-08-11-operation-feedback.md`, Gruppe A, Entwurf A3. P0-1 ist gemergt: `src/ClaudeDo.Ui/Services/OperationStatus.cs` + `src/ClaudeDo.Ui/Views/Controls/OperationIndicator.axaml`.

SCOPE-ÄNDERUNG (Nutzer, 2026-08-12): OnlineInbox Sign-In/Sign-Out ist AUS DEM SCOPE GENOMMEN — vorerst unwichtig. `ViewModels/Modals/Settings/OnlineInboxSettingsViewModel.cs` und die

ClaudeDo-Task: 2356806f-f16e-4652-b615-4562e95c3a65

src/ClaudeDo.Ui/Views/Modals/SettingsModalView.axaml

@@ -280,8 +280,8 @@
                            TextWrapping="Wrap"/>
                 <Button Classes="btn" Content="{loc:Tr settings.files.restoreDefaultAgents}"
                         Command="{Binding Files.RestoreDefaultAgentsCommand}"
-                        IsEnabled="{Binding !Files.IsBusy}"
                         HorizontalAlignment="Left"/>
+                <ctl:OperationIndicator DataContext="{Binding Files.RestoreOp}"/>
               </StackPanel>
               <StackPanel Spacing="6">
                 <TextBlock Classes="section-label" Text="{loc:Tr settings.files.promptsSection}"/>
@@ -502,15 +502,16 @@
                   <TextBox Grid.Column="0" Text="{Binding SessionSkills.InstallUrl, Mode=TwoWay}"
                            PlaceholderText="{loc:Tr settings.skills.installUrlPlaceholder}"/>
                   <Button Grid.Column="1" Classes="btn" Content="{loc:Tr settings.skills.installButton}"
-                          Command="{Binding SessionSkills.InstallCommand}"
-                          IsEnabled="{Binding !SessionSkills.IsBusy}"/>
+                          Command="{Binding SessionSkills.InstallCommand}"/>
                 </Grid>
+                <ctl:OperationIndicator DataContext="{Binding SessionSkills.InstallOp}"/>
               </StackPanel>
 
               <Border BorderBrush="{DynamicResource LineBrush}" BorderThickness="0,1,0,0" Margin="0,2,0,0"/>
 
               <StackPanel Spacing="6">
                 <TextBlock Classes="section-label" Text="{loc:Tr settings.skills.installedSection}"/>
+                <ctl:OperationIndicator DataContext="{Binding SessionSkills.UpdateOp}"/>
                 <ItemsControl ItemsSource="{Binding SessionSkills.Skills}">
                   <ItemsControl.ItemTemplate>
                     <DataTemplate x:DataType="services:SessionSkillDto">