fix(prompts): stop on-disk prompt overrides from freezing forever

EnsureExists blindly seeded ~/.todo-app/prompts/*.md with the bundled
default and never revisited it, so any file created by opening the
Files settings tab shadowed every later default change permanently
(SuggestImprovement/AskUser sections never reached real runs since
2026-06-04). PromptFiles now hashes what a file was seeded/saved with
in prompts/.defaults.json: Classify() tells missing/current-default/
known-past-default/edited apart, ReconcileStaleDefaults() drops files
that only ever matched a superseded default, and real edits are left
alone and surfaced in the Files tab with a diff + reset-to-default
action. QuarantineOrphans() moves stale-named leftovers (agent.md,
planning.md) into prompts/_orphans instead of silently deleting them.
Wired as a Worker startup sweep (PromptFileRecovery) alongside the
existing OrphanRecovery/AttachmentOrphanRecovery services.

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

@@ -297,6 +297,24 @@
                           Command="{Binding Files.OpenPromptCommand}" CommandParameter="WeeklyReport"/>
                 </Grid>
               </StackPanel>
+              <StackPanel Spacing="6" IsVisible="{Binding Files.HasCustomizedPrompts}">
+                <TextBlock Classes="section-label" Text="{loc:Tr settings.files.customizedSection}"/>
+                <TextBlock Classes="meta" Text="{loc:Tr settings.files.customizedHint}" TextWrapping="Wrap"/>
+                <ItemsControl ItemsSource="{Binding Files.CustomizedPrompts}">
+                  <ItemsControl.ItemTemplate>
+                    <DataTemplate>
+                      <StackPanel Spacing="4" Margin="0,0,0,10">
+                        <Grid ColumnDefinitions="*,Auto">
+                          <TextBlock Grid.Column="0" Classes="field-label" Text="{Binding KindName}" VerticalAlignment="Center"/>
+                          <Button Grid.Column="1" Classes="btn" Content="{loc:Tr settings.files.resetToDefault}"
+                                  Command="{Binding ResetCommand}"/>
+                        </Grid>
+                        <TextBlock Classes="path-mono" Text="{Binding DiffPreview}" TextWrapping="Wrap"/>
+                      </StackPanel>
+                    </DataTemplate>
+                  </ItemsControl.ItemTemplate>
+                </ItemsControl>
+              </StackPanel>
               <TextBlock Classes="meta" Text="{Binding Files.StatusMessage}"
                          IsVisible="{Binding Files.StatusMessage, Converter={x:Static StringConverters.IsNotNullOrEmpty}}"/>
             </StackPanel>