refactor(app): compose settings and developer tools

src/AcDream.UI.Abstractions/Panels/Chat/ChatVM.cs

@@ -21,13 +21,14 @@ namespace AcDream.UI.Abstractions.Panels.Chat;
 /// unchanged transcript does not require a queue snapshot each frame.
 /// </para>
 /// </summary>
-public sealed class ChatVM
+public sealed class ChatVM : IDisposable
 {
     /// <summary>Default number of tail entries rendered.</summary>
     public const int DefaultDisplayLimit = 20;
 
     private readonly ChatLog _log;
     private readonly int _displayLimit;
+    private bool _disposed;
 
     /// <summary>
     /// Sender name of the most recent INCOMING Tell. Drives the
@@ -104,6 +105,14 @@ public sealed class ChatVM
             LastOutgoingTellTarget = entry.Sender;
     }
 
+    public void Dispose()
+    {
+        if (_disposed)
+            return;
+        _log.EntryAppended -= OnEntryAppended;
+        _disposed = true;
+    }
+
     /// <summary>
     /// Append a client-side system line to the chat log. Used by
     /// client-handled commands (/help, /clear, future) to surface