refactor(ui): merge the one-expression converters into SimpleConverters.cs

Six files of three lines each. NotNullToBool is gone entirely — Avalonia
ships ObjectConverters.IsNotNull, so TaskRowView binds that directly.

src/ClaudeDo.App/App.axaml

@@ -13,7 +13,6 @@
             </ResourceDictionary.MergedDictionaries>
 
             <!-- Converters -->
-            <converters:NotNullToBoolConverter x:Key="NotNullToBool"/>
             <converters:StrikeIfTrueConverter  x:Key="StrikeIfTrue"/>
             <converters:EqStatusConverter      x:Key="EqStatus"/>
             <converters:UpperCaseConverter     x:Key="UpperCase"/>

src/ClaudeDo.Ui/Converters/BoolToDraftOpacityConverter.cs

@@ -1,13 +0,0 @@
-using System;
-using System.Globalization;
-using Avalonia.Data.Converters;
-
-namespace ClaudeDo.Ui.Converters;
-
-public sealed class BoolToDraftOpacityConverter : IValueConverter
-{
-    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
-        => value is true ? 0.7 : 1.0;
-    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
-        => throw new NotSupportedException();
-}

src/ClaudeDo.Ui/Converters/BoolToItalicConverter.cs

@@ -1,14 +0,0 @@
-using System;
-using System.Globalization;
-using Avalonia.Data.Converters;
-using Avalonia.Media;
-
-namespace ClaudeDo.Ui.Converters;
-
-public sealed class BoolToItalicConverter : IValueConverter
-{
-    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
-        => value is true ? FontStyle.Italic : FontStyle.Normal;
-    public object? ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
-        => throw new NotSupportedException();
-}

src/ClaudeDo.Ui/Converters/NotHeaderRowConverter.cs

@@ -1,18 +0,0 @@
-using System.Globalization;
-using Avalonia.Data.Converters;
-using ClaudeDo.Ui.ViewModels.Islands;
-
-namespace ClaudeDo.Ui.Converters;
-
-// Drives ListBoxItem.Focusable for TasksIslandView's flat Rows list: a HeaderRow container must
-// not be a tab stop, a TaskRowViewModel container must behave like any other row.
-public class NotHeaderRowConverter : IValueConverter
-{
-    public static NotHeaderRowConverter Instance { get; } = new();
-
-    public object Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
-        => value is not HeaderRow;
-
-    public object ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
-        => throw new NotSupportedException();
-}

src/ClaudeDo.Ui/Converters/NotNullToBoolConverter.cs

@@ -1,15 +0,0 @@
-using System.Globalization;
-using Avalonia.Data.Converters;
-
-namespace ClaudeDo.Ui.Converters;
-
-public class NotNullToBoolConverter : IValueConverter
-{
-    public static NotNullToBoolConverter Instance { get; } = new();
-
-    public object Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
-        => value is not null;
-
-    public object ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
-        => throw new NotSupportedException();
-}

src/ClaudeDo.Ui/Converters/SimpleConverters.cs

@@ -0,0 +1,53 @@
+using System.Globalization;
+using Avalonia.Data.Converters;
+using Avalonia.Media;
+using ClaudeDo.Ui.ViewModels.Islands;
+
+namespace ClaudeDo.Ui.Converters;
+
+// One-expression converters. Each is only worth a class because Avalonia XAML can't
+// instantiate a generic FuncValueConverter as a resource; they stay one per type so the
+// x:Key names in App.axaml keep resolving. Anything with real logic gets its own file.
+
+public sealed class UpperCaseConverter : OneWayConverter
+{
+    public static UpperCaseConverter Instance { get; } = new();
+    public override object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
+        => value?.ToString()?.ToUpperInvariant();
+}
+
+public sealed class StrikeIfTrueConverter : OneWayConverter
+{
+    public static StrikeIfTrueConverter Instance { get; } = new();
+    public override object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
+        => value is true ? TextDecorations.Strikethrough : null;
+}
+
+public sealed class BoolToItalicConverter : OneWayConverter
+{
+    public override object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
+        => value is true ? FontStyle.Italic : FontStyle.Normal;
+}
+
+public sealed class BoolToDraftOpacityConverter : OneWayConverter
+{
+    public override object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
+        => value is true ? 0.7 : 1.0;
+}
+
+// Drives ListBoxItem.Focusable for TasksIslandView's flat Rows list: a HeaderRow container must
+// not be a tab stop, a TaskRowViewModel container must behave like any other row.
+public sealed class NotHeaderRowConverter : OneWayConverter
+{
+    public static NotHeaderRowConverter Instance { get; } = new();
+    public override object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
+        => value is not HeaderRow;
+}
+
+public abstract class OneWayConverter : IValueConverter
+{
+    public abstract object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture);
+
+    public object ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
+        => throw new NotSupportedException();
+}

src/ClaudeDo.Ui/Converters/StrikeIfTrueConverter.cs

@@ -1,16 +0,0 @@
-using System.Globalization;
-using Avalonia.Data.Converters;
-using Avalonia.Media;
-
-namespace ClaudeDo.Ui.Converters;
-
-public class StrikeIfTrueConverter : IValueConverter
-{
-    public static StrikeIfTrueConverter Instance { get; } = new();
-
-    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
-        => value is true ? TextDecorations.Strikethrough : null;
-
-    public object ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
-        => throw new NotSupportedException();
-}

src/ClaudeDo.Ui/Converters/UpperCaseConverter.cs

@@ -1,15 +0,0 @@
-using System.Globalization;
-using Avalonia.Data.Converters;
-
-namespace ClaudeDo.Ui.Converters;
-
-public class UpperCaseConverter : IValueConverter
-{
-    public static UpperCaseConverter Instance { get; } = new();
-
-    public object? Convert(object? value, Type targetType, object? parameter, CultureInfo culture)
-        => value?.ToString()?.ToUpperInvariant();
-
-    public object ConvertBack(object? value, Type targetType, object? parameter, CultureInfo culture)
-        => throw new NotSupportedException();
-}

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

@@ -2,6 +2,7 @@
              xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
              xmlns:vm="using:ClaudeDo.Ui.ViewModels.Islands"
              xmlns:ctl="using:ClaudeDo.Ui.Views.Controls"
+             xmlns:conv="using:Avalonia.Data.Converters"
              xmlns:loc="using:ClaudeDo.Ui.Localization"
              x:Class="ClaudeDo.Ui.Views.Islands.TaskRowView"
              x:DataType="vm:TaskRowViewModel">
@@ -187,7 +188,7 @@
             <!-- Chain-after chip: the head-relative fallback when this row isn't rendered as a
                  rail member (planning child, or the head is filtered out of this view). -->
             <Border Classes="chip chip-tag"
-                    IsVisible="{Binding ChainAfterLabel, Converter={StaticResource NotNullToBool}}">
+                    IsVisible="{Binding ChainAfterLabel, Converter={x:Static conv:ObjectConverters.IsNotNull}}">
               <TextBlock>
                 <Run Text="{loc:Tr tasks.chainAfterPrefix}"/>
                 <Run Text=" "/>