feat(ui): colour agent output by kind and stop cutting tool calls at 120 chars

StreamLineFormatter now returns kind-tagged entries (text, tool, edit,
tool result, error, sys, result) instead of a flat string, so the
existing LogKind colours finally apply to stream-json output. Tool
argument/result limit raised from 120 to 500 chars.

src/ClaudeDo.Ui/Converters/LogKindForegroundConverter.cs

@@ -24,15 +24,17 @@ public sealed class LogKindForegroundConverter : IValueConverter
     {
         var key = value is LogKind kind ? kind switch
         {
-            LogKind.Sys    => "TextMuteBrush",
-            LogKind.Tool   => "SageBrush",
-            LogKind.Claude => "TextBrush",
-            LogKind.Stdout => "TextDimBrush",
-            LogKind.Stderr => "BloodBrush",
-            LogKind.Done   => "MossBrightBrush",
-            LogKind.Msg    => "TextDimBrush",
-            LogKind.User   => "AccentBrush",
-            _              => "TextDimBrush",
+            LogKind.Sys        => "TextMuteBrush",
+            LogKind.Tool       => "SageBrush",
+            LogKind.Claude     => "TextBrush",
+            LogKind.Stdout     => "TextDimBrush",
+            LogKind.Stderr     => "BloodBrush",
+            LogKind.Done       => "MossBrightBrush",
+            LogKind.Msg        => "TextDimBrush",
+            LogKind.User       => "AccentBrush",
+            LogKind.Edit       => "AmberBrush",
+            LogKind.ToolResult => "TextMuteBrush",
+            _                  => "TextDimBrush",
         } : "TextDimBrush";
 
         return Resolve(key) ?? AvaloniaProperty.UnsetValue;