feat(claude-do): merge feat(ui): "Worktree öffnen" im Kontextmenü der Task-Zeile

ClaudeDo-Task: 9be17e29e0b54f42ba9385b0cebe89d5

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

@@ -20,6 +20,7 @@ public sealed partial class TaskRowViewModel : ViewModelBase
     [ObservableProperty] private string? _branch;
     [ObservableProperty] private string? _diffStat;
     [ObservableProperty] private ClaudeDo.Data.Models.WorktreeState? _worktreeState;
+    [ObservableProperty] private string? _worktreePath;
     [ObservableProperty] private DateTime? _scheduledFor;
     [ObservableProperty] private int _diffAdditions;
     [ObservableProperty] private int _diffDeletions;
@@ -179,6 +180,9 @@ public sealed partial class TaskRowViewModel : ViewModelBase
     // placeholder so the menu wiring is uniform; always null until a real gate exists.
     public string? QuickSessionDisabledReason => null;
 
+    public bool CanOpenWorktree => !string.IsNullOrWhiteSpace(WorktreePath);
+    public string? OpenWorktreeDisabledReason => CanOpenWorktree ? null : Loc.T("tasks.reasonNoWorktree");
+
     public string? RefineDisabledReason
     {
         get
@@ -425,6 +429,11 @@ public sealed partial class TaskRowViewModel : ViewModelBase
 
     partial void OnNumberChanged(int value)        => OnPropertyChanged(nameof(ShowNumberBadge));
     partial void OnBranchChanged(string? value)    => OnPropertyChanged(nameof(HasBranch));
+    partial void OnWorktreePathChanged(string? value)
+    {
+        OnPropertyChanged(nameof(CanOpenWorktree));
+        OnPropertyChanged(nameof(OpenWorktreeDisabledReason));
+    }
     partial void OnWorktreeStateChanged(ClaudeDo.Data.Models.WorktreeState? value)
     {
         OnPropertyChanged(nameof(IsParked));
@@ -485,6 +494,7 @@ public sealed partial class TaskRowViewModel : ViewModelBase
         Branch            = t.Worktree?.BranchName;
         DiffStat          = t.Worktree?.DiffStat;
         WorktreeState     = t.Worktree?.State;
+        WorktreePath      = t.Worktree?.Path;
         ScheduledFor      = t.ScheduledFor;
         DiffAdditions     = add;
         DiffDeletions     = del;

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

@@ -1429,6 +1429,21 @@ public sealed partial class TasksIslandViewModel : ViewModelBase, IDisposable
         OpenConPtySessionRequested?.Invoke(row.Id);
     }
 
+    [RelayCommand]
+    private void OpenTaskWorktree(TaskRowViewModel? row)
+    {
+        if (row?.WorktreePath is not { } path || string.IsNullOrWhiteSpace(path)) return;
+        try
+        {
+            System.Diagnostics.Process.Start(new System.Diagnostics.ProcessStartInfo
+            {
+                FileName = path,
+                UseShellExecute = true,
+            });
+        }
+        catch (Exception ex) { ErrorReported?.Invoke(Loc.T("vm.tasksIsland.openWorktreeFailed", ex.Message)); }
+    }
+
     [RelayCommand]
     private async Task ResumePlanningSessionAsync(TaskRowViewModel? row)
     {