feat(ui): Erststart-Banner und Textkette Repo→Task→Queue→Review (UX-Struktur C)

HasNoLinkedRepo on ListsIslandViewModel drives a dismiss-less banner under the
Lists-Island header when no User list has a linked repo; recomputed on load
and after list CRUD / list-settings save. Sharpens the #192 empty-state texts
into one readable chain (banner → no-repo list → repo-linked list) and adds a
line to the WorkConsole review gate spelling out that Approve also merges the
whole unit.

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

@@ -186,6 +186,14 @@ public sealed partial class ListsIslandViewModel : ViewModelBase, IDisposable
     [ObservableProperty] private string _searchText = "";
     [ObservableProperty] private ListNavItemViewModel? _selectedList;
 
+    /// <summary>True whenever no User list has a linked <c>WorkingDir</c> — drives the no-repo
+    /// banner. Smart/Virtual lists never count. Recomputed after every load and every
+    /// list CRUD / list-settings save; never persisted, no dismiss state.</summary>
+    [ObservableProperty] private bool _hasNoLinkedRepo = true;
+
+    private void RecomputeHasNoLinkedRepo() =>
+        HasNoLinkedRepo = UserLists.All(r => string.IsNullOrWhiteSpace(r.WorkingDir));
+
     public string UserName { get; } = Environment.UserName;
     public string MachineName { get; } = Environment.MachineName;
     public string MachineNameLocal => Loc.T("vm.lists.localSuffix", MachineName);
@@ -291,6 +299,7 @@ public sealed partial class ListsIslandViewModel : ViewModelBase, IDisposable
         }
         finally { OperationTiming.Shared.Record("db", "ListsIsland.LoadAsync", sw.Elapsed, ok); }
 
+        RecomputeHasNoLinkedRepo();
         await RefreshCountsAsync(ct);
         SelectedList = Items.FirstOrDefault();
     }
@@ -372,6 +381,7 @@ public sealed partial class ListsIslandViewModel : ViewModelBase, IDisposable
         Items.Add(item);
         UserLists.Add(item);
         SelectedList = item;
+        RecomputeHasNoLinkedRepo();
 
         if (Dialogs is not null && _services is not null)
         {
@@ -474,6 +484,7 @@ public sealed partial class ListsIslandViewModel : ViewModelBase, IDisposable
             row.DefaultCommitType = entity.DefaultCommitType;
             row.IsManual = entity.IsManual;
             row.FindingsTracked = entity.FindingsTracked;
+            RecomputeHasNoLinkedRepo();
         }
         catch { /* best-effort refresh */ }
     }
@@ -505,5 +516,6 @@ public sealed partial class ListsIslandViewModel : ViewModelBase, IDisposable
 
         UserLists.Insert(insertAt, item);
         Items.Insert(SmartLists.Count + insertAt, item);
+        RecomputeHasNoLinkedRepo();
     }
 }