feat(notes): notes get their own list, a day log and an Enter chain

The editor was reachable from one button that only appeared in My Day,
which is how it got forgotten. It is now a permanent sidebar entry next
to My Day and Planned, and it fills the tasks island rather than the
details pane, because a note list is content.

Inside, the date picker is gone: today sits at the top with the capture
box, older days follow as dated groups. Enter in a note saves it and
opens the next one, Shift+Enter breaks the line so notes can be several,
Backspace on an empty note deletes it and steps back up. Deleting also
has a visible hover button instead of only "clear the text and hope".
Agent-written notes carry a marker.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

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

@@ -20,7 +20,6 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
     private readonly IDbContextFactory<ClaudeDoDbContext> _dbFactory;
     private readonly IWorkerClient _worker;
     private readonly IServiceProvider _services;
-    private readonly INotesApi _notesApi;
     private readonly MergeCoordinator _merge;
 
     // ── Section view models ───────────────────────────────────────────────────
@@ -39,29 +38,20 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
     private readonly Action<string, string?> _workerPlanningMergeAbortedHandler;
     private readonly Action<string> _workerPlanningCompletedHandler;
 
-    [ObservableProperty] private bool _isNotesMode;
     [ObservableProperty] private bool _isPrepMode;
 
-    public bool IsTaskDetailVisible => !IsNotesMode && !IsPrepMode;
+    public bool IsTaskDetailVisible => !IsPrepMode;
 
-    /// <summary>Centered placeholder shown when no task is selected — hidden in Notes/Prep mode,
+    /// <summary>Centered placeholder shown when no task is selected — hidden in Prep mode,
     /// where <see cref="IsTaskDetailVisible"/> is already false.</summary>
     public bool IsEmptyStateVisible => Task is null && IsTaskDetailVisible;
 
-    partial void OnIsNotesModeChanged(bool value)
-    {
-        OnPropertyChanged(nameof(IsTaskDetailVisible));
-        OnPropertyChanged(nameof(IsEmptyStateVisible));
-    }
-
     partial void OnIsPrepModeChanged(bool value)
     {
         OnPropertyChanged(nameof(IsTaskDetailVisible));
         OnPropertyChanged(nameof(IsEmptyStateVisible));
     }
 
-    public NotesEditorViewModel Notes { get; private set; } = null!;
-
     // Current task row (set by IslandsShellViewModel via Bind)
     [ObservableProperty]
     [NotifyCanExecuteChangedFor(nameof(EnqueueCommand))]
@@ -324,13 +314,11 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
         IDbContextFactory<ClaudeDoDbContext> dbFactory,
         IWorkerClient worker,
         IServiceProvider services,
-        INotesApi notesApi,
         MergeCoordinator merge)
     {
         _dbFactory = dbFactory;
         _worker = worker;
         _services = services;
-        _notesApi = notesApi;
         _merge = merge;
 
         Monitor = new TaskMonitorViewModel(dbFactory, worker);
@@ -374,8 +362,6 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
             if (e.PropertyName == nameof(OperationStatus.IsRunning)) ParkReviewCommand.NotifyCanExecuteChanged();
         };
 
-        Notes = new NotesEditorViewModel(_notesApi);
-        Notes.ErrorReported += msg => { if (ShowErrorAsync is not null) _ = ShowErrorAsync(msg); };
         Subtasks.CollectionChanged += (_, _) => NotifyStepsChanged();
         Subtasks.CollectionChanged += (_, _) => Merge.SyncChildOutcomes(HasChildOutcomes, Subtasks.Count);
         Attachments.CollectionChanged += (_, _) => OnPropertyChanged(nameof(FilesBadge));
@@ -592,18 +578,9 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
         catch { }
     }
 
-    public void ShowNotes()
-    {
-        Bind(null, "notes");
-        IsPrepMode = false;
-        IsNotesMode = true;
-        _ = Notes.LoadDayAsync(DateOnly.FromDateTime(DateTime.Today));
-    }
-
     public void ShowPrep()
     {
         Bind(null, "prep");
-        IsNotesMode = false;
         IsPrepMode = true;
         _ = Prep.LoadLastPrepLogIfEmptyAsync();
     }
@@ -612,7 +589,6 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase, IDisposable
     /// logged with the bind timing so rebind churn can be attributed to a trigger.</param>
     public void Bind(TaskRowViewModel? row, string source = "?")
     {
-        IsNotesMode = false;
         IsPrepMode = false;
         _loadCts?.Cancel();
         _loadCts?.Dispose();