feat(ui): rework work console — single Session tab, right-aligned header, turns x/y

- Merge "Actions" + "Session" into one state-aware Session tab: review controls
  on top, then merge/worktree management, then child outcomes — each gated on the
  current state, with an empty-state hint when there's nothing to manage. This is
  the home the real merge/diff work (task 09eb5d52) will slot into.
- Move the model · turns · diff info block to the right of the title bar.
- Show turns as current/max using the resolved turn budget (task → list → global).
- Output terminal now fills the console body cleanly: clip the console to its
  rounded corners and inset the embedded terminal instead of clipping its bottom.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

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

@@ -133,23 +133,42 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase
             EditableTitle, EditableDescription, Subtasks.Select(s => (s.Title, s.Done)));
 
     // ── Work console (redesign) ────────────────────────────────────────
+    // Two tabs: Output (live log) and Session (review + merge/worktree +
+    // outcomes, each section gated on the relevant state).
     [ObservableProperty]
     [NotifyPropertyChangedFor(nameof(IsOutputTab))]
-    [NotifyPropertyChangedFor(nameof(IsActionsTab))]
     [NotifyPropertyChangedFor(nameof(IsSessionTab))]
     private string _selectedTab = "output";
 
     public bool IsOutputTab  => SelectedTab == "output";
-    public bool IsActionsTab => SelectedTab == "actions";
     public bool IsSessionTab => SelectedTab == "session";
 
     [RelayCommand]
     private void SelectTab(string? tab) => SelectedTab = tab ?? "output";
 
-    public string TurnsText   => $"{Turns} turns";
+    // Merge/worktree controls only matter once there's a worktree to manage
+    // (standalone task), or a planning parent / improvement parent with children.
+    public bool ShowMergeSection =>
+        WorktreePath != null || Task?.IsPlanningParent == true || HasChildOutcomes;
+
+    // Nothing to manage yet (idle/queued/running standalone): show a hint.
+    public bool ShowSessionEmpty =>
+        !IsWaitingForReview && !ShowMergeSection && !HasChildOutcomes;
+
+    private void NotifySessionSections()
+    {
+        OnPropertyChanged(nameof(ShowMergeSection));
+        OnPropertyChanged(nameof(ShowSessionEmpty));
+    }
+
+    public string TurnsText   => $"{Turns}/{EffectiveMaxTurns}";
     public string DiffAddText => $"+{DiffAdditions}";
     public string DiffDelText => $"-{DiffDeletions}";
 
+    // Resolved turn budget: per-task override → list default → global default.
+    public int EffectiveMaxTurns =>
+        TaskMaxTurns is decimal t ? (int)t : (_listMaxTurns ?? _globalMaxTurns);
+
     public bool ShowRoadblock => IsFailed || IsCancelled;
     public string RoadblockMessage =>
         IsFailed ? "The session ended with an error." :
@@ -201,6 +220,7 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase
         OnPropertyChanged(nameof(IsAgentSectionEnabled));
         OnPropertyChanged(nameof(ShowRoadblock));
         OnPropertyChanged(nameof(RoadblockMessage));
+        NotifySessionSections();
     }
     [ObservableProperty] private string? _model;
 
@@ -223,7 +243,13 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase
     private string? _listAgentName;
 
     partial void OnTaskModelSelectionChanged(string? value) { RecomputeModelBadge(); QueueAgentSave(); }
-    partial void OnTaskMaxTurnsChanged(decimal? value) { RecomputeTurnsBadge(); QueueAgentSave(); }
+    partial void OnTaskMaxTurnsChanged(decimal? value)
+    {
+        RecomputeTurnsBadge();
+        OnPropertyChanged(nameof(EffectiveMaxTurns));
+        OnPropertyChanged(nameof(TurnsText));
+        QueueAgentSave();
+    }
 
     private void RecomputeModelBadge()
     {
@@ -460,6 +486,7 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase
         {
             RecomputeCanMergeAll();
             ReviewCombinedDiffCommand.NotifyCanExecuteChanged();
+            NotifySessionSections();
         };
 
         PrepLog.CollectionChanged += (_, _) => OnPropertyChanged(nameof(ShowPrepEmptyState));
@@ -637,6 +664,8 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase
             RecomputeModelBadge();
             RecomputeTurnsBadge();
             RecomputeAgentBadge();
+            OnPropertyChanged(nameof(EffectiveMaxTurns));
+            OnPropertyChanged(nameof(TurnsText));
         }
         finally
         {
@@ -1113,8 +1142,11 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase
     {
         OpenDiffCommand.NotifyCanExecuteChanged();
         OpenWorktreeCommand.NotifyCanExecuteChanged();
+        NotifySessionSections();
     }
 
+    partial void OnTaskChanged(TaskRowViewModel? value) => NotifySessionSections();
+
     [RelayCommand]
     private void CloseDetails() => CloseDetail?.Invoke();