feat(ui): always-visible Steps section at top of DetailsIsland with add-step input

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

@@ -110,6 +110,8 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase
     public ObservableCollection<LogLineViewModel> Log { get; } = new();
     public ObservableCollection<SubtaskRowViewModel> Subtasks { get; } = new();
 
+    [ObservableProperty] private string _newSubtaskTitle = "";
+
     // Claude CLI stream-json parser + buffer for partial text deltas
     private readonly StreamLineFormatter _formatter = new();
     private readonly StringBuilder _claudeBuf = new();
@@ -487,6 +489,30 @@ public sealed partial class DetailsIslandViewModel : ViewModelBase
         CloseDetail?.Invoke();
     }
 
+    [RelayCommand]
+    private async System.Threading.Tasks.Task AddSubtaskAsync()
+    {
+        if (Task is null) return;
+        var title = NewSubtaskTitle?.Trim();
+        if (string.IsNullOrEmpty(title)) return;
+
+        var entity = new ClaudeDo.Data.Models.SubtaskEntity
+        {
+            Id = Guid.NewGuid().ToString(),
+            TaskId = Task.Id,
+            Title = title,
+            Completed = false,
+            OrderNum = Subtasks.Count,
+            CreatedAt = DateTime.UtcNow,
+        };
+
+        await using var ctx = _dbFactory.CreateDbContext();
+        await new SubtaskRepository(ctx).AddAsync(entity);
+
+        Subtasks.Add(new SubtaskRowViewModel { Id = entity.Id, Title = entity.Title, Done = entity.Completed });
+        NewSubtaskTitle = "";
+    }
+
     [RelayCommand]
     private async System.Threading.Tasks.Task SaveNotesAsync()
     {

src/ClaudeDo.Ui/Views/Islands/DetailsIslandView.axaml

@@ -88,25 +88,27 @@
       </Grid>
     </Border>
 
-    <!-- ── Main body: agent strip (auto) · terminal (flex) · steps+notes (auto/capped) · agent overrides (auto) ── -->
-    <Grid RowDefinitions="Auto,*,Auto,Auto">
-
-      <!-- Agent strip -->
-      <islands:AgentStripView Grid.Row="0"/>
-
-      <!-- Session terminal — fills remaining vertical space -->
-      <islands:SessionTerminalView Grid.Row="1" MinHeight="220" Margin="0,0,0,0"/>
-
-      <!-- Steps + Notes in a capped scroller so they never squeeze the terminal -->
-      <ScrollViewer Grid.Row="2" MaxHeight="240"
-                    VerticalScrollBarVisibility="Auto">
-        <StackPanel Spacing="0">
-
-          <!-- Subtasks section -->
-          <StackPanel Margin="18,12,18,0"
+    <!-- ── Steps section (always visible, above the terminal) ── -->
+    <Border DockPanel.Dock="Top"
+            Padding="18,10,18,10"
+            BorderBrush="{DynamicResource LineBrush}"
+            BorderThickness="0,0,0,1">
+      <StackPanel Spacing="6">
+        <TextBlock Classes="section-label" Text="STEPS" Margin="0,0,0,2"/>
+        <TextBox Text="{Binding NewSubtaskTitle, Mode=TwoWay}"
+                 PlaceholderText="Add a step..."
+                 Padding="8"
+                 Background="{DynamicResource Surface2Brush}"
+                 BorderBrush="{DynamicResource LineBrush}"
+                 BorderThickness="1"
+                 CornerRadius="6">
+          <TextBox.KeyBindings>
+            <KeyBinding Gesture="Enter" Command="{Binding AddSubtaskCommand}"/>
+          </TextBox.KeyBindings>
+        </TextBox>
+        <ScrollViewer MaxHeight="180"
+                      VerticalScrollBarVisibility="Auto"
                       IsVisible="{Binding Subtasks.Count}">
-            <TextBlock Classes="section-label" Text="STEPS"
-                       Margin="0,0,0,6"/>
           <ItemsControl ItemsSource="{Binding Subtasks}">
             <ItemsControl.ItemTemplate>
               <DataTemplate DataType="vm:SubtaskRowViewModel">
@@ -132,9 +134,22 @@
               </DataTemplate>
             </ItemsControl.ItemTemplate>
           </ItemsControl>
+        </ScrollViewer>
       </StackPanel>
+    </Border>
 
-          <!-- Notes section -->
+    <!-- ── Main body: agent strip (auto) · terminal (flex) · notes (auto/capped) · agent overrides (auto) ── -->
+    <Grid RowDefinitions="Auto,*,Auto,Auto">
+
+      <!-- Agent strip -->
+      <islands:AgentStripView Grid.Row="0"/>
+
+      <!-- Session terminal — fills remaining vertical space -->
+      <islands:SessionTerminalView Grid.Row="1" MinHeight="220" Margin="0,0,0,0"/>
+
+      <!-- Notes in a capped scroller so it never squeezes the terminal -->
+      <ScrollViewer Grid.Row="2" MaxHeight="180"
+                    VerticalScrollBarVisibility="Auto">
         <StackPanel Margin="18,12,18,12">
           <TextBlock Classes="section-label" Text="NOTES" Margin="0,0,0,6"/>
           <TextBox Text="{Binding Notes, Mode=TwoWay}"
@@ -149,8 +164,6 @@
                    CornerRadius="8"
                    LostFocus="NotesLostFocus"/>
         </StackPanel>
-
-        </StackPanel>
       </ScrollViewer>
 
       <!-- Agent settings overrides — own row so expanding shrinks the terminal (down to its MinHeight) instead of scrolling inside the capped section -->