feat(ui): make sidebar folder hierarchy readable

Lists default to the Text icon instead of the folder icon, rows align
across depths with a guide line per open folder, folder names are
semibold, folder counts only show while collapsed and zero counts hide.

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

@@ -16,9 +16,16 @@ public sealed partial class ListFolderNavItemViewModel : ViewModelBase
     public string? ParentFolderId { get; set; }
     [ObservableProperty] private string _name = "";
     [ObservableProperty] private string _iconKey = "Folder";
-    [ObservableProperty] private bool _isCollapsed;
+    [ObservableProperty]
+    [NotifyPropertyChangedFor(nameof(ShowCount))]
+    private bool _isCollapsed;
     // Sum of the descendant lists' counts, recursive — a collapsed folder still shows what's inside it.
-    [ObservableProperty] private int _count;
+    [ObservableProperty]
+    [NotifyPropertyChangedFor(nameof(ShowCount))]
+    private int _count;
+
+    /// <summary>Badge only while collapsed — expanded, the children show their own counts.</summary>
+    public bool ShowCount => IsCollapsed && Count > 0;
     // Set while a dragged list row hovers over the middle of this folder header (move-into-folder).
     [ObservableProperty] private bool _isDropTarget;
     // Insert-position hints for a drop next to the folder instead of into it. Drawn around the

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

@@ -8,7 +8,12 @@ public sealed partial class ListNavItemViewModel : ViewModelBase
     public required string Id { get; init; }
     public required ListKind Kind { get; init; }
     [ObservableProperty] private string _name = "";
-    [ObservableProperty] private int _count;
+    [ObservableProperty]
+    [NotifyPropertyChangedFor(nameof(HasCount))]
+    private int _count;
+
+    /// <summary>Hides a "0" badge — an empty list reads as noise next to the real counts.</summary>
+    public bool HasCount => Count > 0;
     [ObservableProperty] private bool _isActive;
     [ObservableProperty] private string? _workingDir;
     [ObservableProperty] private string _defaultCommitType = CommitTypeRegistry.DefaultType;

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

@@ -30,6 +30,9 @@ public sealed partial class ListsIslandViewModel : ViewModelBase, IDisposable
     /// <summary>Icon key a folder falls back to when it has none of its own.</summary>
     public const string ListFolderIcon = "Folder";
 
+    /// <summary>Icon key a list falls back to — deliberately not the folder icon, so the two stay distinguishable.</summary>
+    public const string ListIcon = ListSettingsModalViewModel.DefaultIcon;
+
     private readonly IDbContextFactory<ClaudeDoDbContext> _dbFactory;
     private readonly IServiceProvider? _services;
     private readonly IWorkerClient? _worker;
@@ -368,7 +371,7 @@ public sealed partial class ListsIslandViewModel : ViewModelBase, IDisposable
                     Id = $"user:{l.Id}",
                     Name = l.Name,
                     Kind = ListKind.User,
-                    IconKey = l.Icon ?? "Folder",
+                    IconKey = l.Icon ?? ListIcon,
                     WorkingDir = l.WorkingDir,
                     DefaultCommitType = l.DefaultCommitType,
                     IsManual = l.IsManual,
@@ -473,7 +476,7 @@ public sealed partial class ListsIslandViewModel : ViewModelBase, IDisposable
             Id = $"user:{entity.Id}",
             Name = entity.Name,
             Kind = ListKind.User,
-            IconKey = "Folder",
+            IconKey = ListIcon,
             WorkingDir = entity.WorkingDir,
             DefaultCommitType = entity.DefaultCommitType,
         };
@@ -840,7 +843,7 @@ public sealed partial class ListsIslandViewModel : ViewModelBase, IDisposable
             row.DefaultCommitType = entity.DefaultCommitType;
             row.IsManual = entity.IsManual;
             row.FindingsTracked = entity.FindingsTracked;
-            row.IconKey = entity.Icon ?? "Folder";
+            row.IconKey = entity.Icon ?? ListIcon;
             row.HasTicketProject = hasTicketProject;
             RecomputeHasNoLinkedRepo();
         }
@@ -886,7 +889,7 @@ public sealed partial class ListsIslandViewModel : ViewModelBase, IDisposable
             Id = $"user:{entity.Id}",
             Name = entity.Name,
             Kind = ListKind.User,
-            IconKey = entity.Icon ?? "Folder",
+            IconKey = entity.Icon ?? ListIcon,
             WorkingDir = entity.WorkingDir,
             DefaultCommitType = entity.DefaultCommitType,
             IsManual = entity.IsManual,