fix(ui): Import-Erfolgsmeldung nicht mehr als Fehler einfaerben

Der Footer-Strip trug schon immer ein Level, es gab nur keinen
Einstiegspunkt jenseits von FlashFooterError. "3 neue Tasks" in Rot
liest sich als Fehlschlag.

src/ClaudeDo.Ui/ViewModels/Islands/ListsIslandViewModel.cs

@@ -33,6 +33,9 @@ public sealed partial class ListsIslandViewModel : ViewModelBase, IDisposable
     // mirrors TasksIslandViewModel.ErrorReported — surfaces modal-owned failures in the footer strip.
     public event Action<string>? ErrorReported;
 
+    // Same strip, but for an action that succeeded and has a result worth showing.
+    public event Action<string>? SuccessReported;
+
     public IDialogService? Dialogs { get; set; }
 
     [RelayCommand]
@@ -528,10 +531,7 @@ public sealed partial class ListsIslandViewModel : ViewModelBase, IDisposable
         try
         {
             var result = await _worker.ImportTicketsAsync(rawId);
-            // No FlashFooterInfo variant exists in this project — the footer strip only has an
-            // error channel (ErrorReported -> IslandsShellViewModel.FlashFooterError). A silent
-            // success is the worse option, so the result reuses the same channel.
-            ErrorReported?.Invoke(Loc.T("lists.importTicketsResult", result.Examined, result.Created));
+            SuccessReported?.Invoke(Loc.T("lists.importTicketsResult", result.Examined, result.Created));
         }
         catch (Exception ex)
         {