feat(lists): selectable list/folder colors with accent-aware swatches and custom picker

tests/ClaudeDo.Ui.Tests/ViewModels/ListSettingsModalViewModelTests.cs

@@ -37,6 +37,7 @@ public class ListSettingsModalViewModelTests
         public TicketSettingsDto? TicketSettings = new("http://ticket.example", true);
         public Func<Task<List<TicketProjectDto>>>? TicketProjectsFactory;
         public UpdateListConfigDto? SavedListConfig;
+        public UpdateListDto? SavedList;
 
         public Exception? GetListConfigThrows;
 
@@ -52,6 +53,12 @@ public class ListSettingsModalViewModelTests
         public override Task<List<TicketProjectDto>> GetTicketProjectsAsync() =>
             TicketProjectsFactory?.Invoke() ?? Task.FromResult(new List<TicketProjectDto>());
 
+        public override Task UpdateListAsync(UpdateListDto dto)
+        {
+            SavedList = dto;
+            return Task.CompletedTask;
+        }
+
         public override Task UpdateListConfigAsync(UpdateListConfigDto dto)
         {
             SavedListConfig = dto;
@@ -95,6 +102,62 @@ public class ListSettingsModalViewModelTests
         Assert.False(ListSettingsModalViewModel.IsKnownIcon("mdi:NoSuchIcon"));
     }
 
+    [Fact]
+    public void Color_SwatchAndCustomStaySynced()
+    {
+        var vm = new ListSettingsModalViewModel(new CountingWorker(), NewFactory());
+
+        vm.SelectedSwatch = "Swatch3";
+        Assert.Equal("Swatch3", vm.SelectedColor);
+        Assert.False(vm.IsCustomColor);
+
+        vm.CustomColor = Avalonia.Media.Color.Parse("#112233");
+        Assert.Equal("#112233", vm.SelectedColor);
+        Assert.True(vm.IsCustomColor);
+        Assert.Null(vm.SelectedSwatch);
+
+        vm.SelectedSwatch = null; // what the ListBox pushes while a custom hex is current
+        Assert.Equal("#112233", vm.SelectedColor);
+
+        vm.SelectedSwatch = "";
+        Assert.Equal("", vm.SelectedColor);
+    }
+
+    [Fact]
+    public async Task Save_List_SendsColor_AndBlankMeansNull()
+    {
+        var worker = new CountingWorker();
+        var vm = new ListSettingsModalViewModel(worker, NewFactory());
+        await vm.LoadAsync("l1", "List One", "", "feat", color: "Swatch2");
+
+        Assert.Equal("Swatch2", vm.SelectedColor);
+        await vm.SaveCommand.ExecuteAsync(null);
+        Assert.Equal("Swatch2", worker.SavedList!.Color);
+
+        vm.SelectedSwatch = "";
+        await vm.SaveCommand.ExecuteAsync(null);
+        Assert.Null(worker.SavedList!.Color);
+    }
+
+    [Fact]
+    public async Task Save_Folder_PersistsCustomColor()
+    {
+        var factory = NewFactory();
+        await using (var ctx = await factory.CreateDbContextAsync())
+        {
+            await new ClaudeDo.Data.Repositories.ListRepository(ctx).AddFolderAsync(
+                new ClaudeDo.Data.Models.ListFolderEntity { Id = "f1", Name = "Group", CreatedAt = DateTime.UtcNow });
+        }
+
+        var vm = new ListSettingsModalViewModel(new CountingWorker(), factory);
+        vm.BeginLoadFolder("f1", "Group", null, "Swatch1");
+        vm.CustomColor = Avalonia.Media.Color.Parse("#A1B2C3");
+        await vm.SaveCommand.ExecuteAsync(null);
+
+        await using var check = await factory.CreateDbContextAsync();
+        Assert.Equal("#A1B2C3", (await check.ListFolders.FindAsync("f1"))!.Color);
+    }
+
     [Fact]
     public async Task LoadAsync_CallsGetListConfig_ExactlyOnce()
     {