feat(ui): reveal a task by id from anywhere

src/ClaudeDo.Ui/ViewModels/IslandsShellViewModel.cs

@@ -43,6 +43,9 @@ public sealed partial class IslandsShellViewModel : ViewModelBase, IDisposable
     // Layer C seam: composition root sets the factory; the dialog service shows the resolver.
     public Func<string, ClaudeDo.Ui.ViewModels.Conflicts.ConflictResolverViewModel>? ConflictResolverFactory { get; set; }
 
+    // Set by MainWindow so a reveal can bring the main window to the foreground.
+    public Action? BringToFront { get; set; }
+
     // Single dialog seam (set by MainWindow); propagated to the lists island.
     private IDialogService? _dialogs;
     public IDialogService? Dialogs
@@ -55,6 +58,33 @@ public sealed partial class IslandsShellViewModel : ViewModelBase, IDisposable
         }
     }
 
+    public async Task RevealTaskAsync(string taskId)
+    {
+        if (Tasks is null || Lists is null) { BringToFront?.Invoke(); return; }
+
+        string? listId = null;
+        if (_dbFactory is not null)
+        {
+            try
+            {
+                await using var ctx = await _dbFactory.CreateDbContextAsync();
+                var entity = await ctx.Tasks.AsNoTracking().FirstOrDefaultAsync(t => t.Id == taskId);
+                listId = entity?.ListId;
+            }
+            catch { /* best-effort list resolution */ }
+        }
+
+        if (listId is not null)
+        {
+            var navItem = Lists.Items.FirstOrDefault(i => i.Id == $"user:{listId}");
+            if (navItem is not null && !ReferenceEquals(Lists.SelectedList, navItem))
+                Lists.SelectedList = navItem; // raises SelectionChanged → Tasks.LoadForList
+        }
+
+        await Tasks.SelectByIdAsync(taskId);
+        BringToFront?.Invoke();
+    }
+
     public async Task RequestConflictResolutionAsync(string taskId, string targetBranch)
     {
         if (ConflictResolverFactory is null || Dialogs is null) return;