refactor(ui): Material icons for list, folder and smart-list icon keys with legacy mapping

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

src/ClaudeDo.Ui/ViewModels/Modals/ListSettingsModalViewModel.cs

@@ -157,12 +157,11 @@ public sealed partial class ListSettingsModalViewModel : ViewModelBase
     /// <summary>Default icon for folders, kept apart from <see cref="DefaultIcon"/> so lists never look like folders.</summary>
     public const string DefaultFolderIcon = "Folder";
 
-    // Curated subset of the Icon.* geometry library in IslandStyles.axaml — window chrome and
-    // pure stroke icons (PathIcon fills, so those render invisible) are deliberately left out.
-    // Grouped by theme so the picker grid reads in rows; every entry needs a matching
-    // "Icon.<key>" StreamGeometry or it renders as an empty slot.
-    public static readonly string[] IconOptions =
-    [
+    // Curated picker set, grouped by theme so the grid reads in rows. Each legacy key is offered as its
+    // MDI replacement (IconKeyConverter.LegacyKinds); "Dot" and "Folder" stay bare because they are the
+    // default-icon constants the sidebar compares against.
+    public static readonly string[] IconOptions = new[]
+    {
         // general
         "Dot", "Folder", "Star", "Sun", "Calendar", "Clock", "Inbox", "Mail", "Text", "Search", "Grid",
         // dev
@@ -171,7 +170,7 @@ public sealed partial class ListSettingsModalViewModel : ViewModelBase
         "Activity", "Eye", "Check", "Warning", "Chart", "Rocket", "Bulb", "Broom", "AgentSuggested", "Settings",
         // things
         "Box", "Truck", "MapPin", "Camera", "Image", "Barcode", "Skull",
-    ];
+    }.Select(k => k is DefaultIcon or DefaultFolderIcon ? k : IconKeyConverter.MdiPrefix + IconKeyConverter.LegacyKinds[k]).ToArray();
 
     /// <summary>Cap on search hits so the picker's WrapPanel stays responsive.</summary>
     public const int MaxIconResults = 200;
@@ -195,9 +194,10 @@ public sealed partial class ListSettingsModalViewModel : ViewModelBase
     // Separate from Icon: swapping Icons makes the ListBox push null here, which must not wipe the choice.
     [ObservableProperty] private string? _selectedIconOption = DefaultIcon;
 
-    /// <summary>True for a curated key or an existing "mdi:" kind.</summary>
+    /// <summary>True for a curated key, a legacy bare key still stored in the DB, or an existing "mdi:" kind.</summary>
     public static bool IsKnownIcon(string? key) =>
         key is not null && (IconOptions.Contains(key)
+            || IconKeyConverter.LegacyKinds.ContainsKey(key)
             || (key.StartsWith(IconKeyConverter.MdiPrefix, StringComparison.Ordinal)
                 && Enum.TryParse<MaterialIconKind>(key[IconKeyConverter.MdiPrefix.Length..], out _)));