feat(ui): complete Batch 2 — LiveText display, start feedback, modal theming, ListEditor config

- Replace LiveLines with formatted LiveText + StreamLineFormatter
- Add log reload from disk for completed tasks
- Add start feedback (starting.../running) on detail and list views
- Apply dark theme (WindowBgBrush, AccentBrush) to editor modals
- Add model/system-prompt/agent-path config to ListEditorView
- Wire config loading/saving in MainWindowViewModel
- Fix duplicate AgentInfo DTO (use canonical Data.Models version)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/ClaudeDo.Ui/Services/WorkerClient.cs

@@ -1,5 +1,6 @@
 using System.Collections.ObjectModel;
 using Avalonia.Threading;
+using ClaudeDo.Data.Models;
 using CommunityToolkit.Mvvm.ComponentModel;
 using Microsoft.AspNetCore.SignalR.Client;
 
@@ -228,5 +229,3 @@ public partial class WorkerClient : ObservableObject, IAsyncDisposable
         public DateTime StartedAt { get; set; }
     }
 }
-
-public record AgentInfo(string Name, string Description, string Path);