fix #213: complete suicide and framerate presentation

Translate suicide response 0x004A as retail's successful self-kill notice. Port /framerate onto the authored SmartBox FPS element with live two-decimal FPS and DEG values, keep diagnostic window chrome independent, and synchronize command-driven settings without discarding panel drafts.

Co-Authored-By: Codex <codex@openai.com>

src/AcDream.App/UI/Layout/RetailFpsController.cs

@@ -0,0 +1,79 @@
+using System.Globalization;
+
+namespace AcDream.App.UI.Layout;
+
+/// <summary>
+/// Binds retail's SmartBox frame-rate display to the authored text element from
+/// <c>LayoutDesc 0x2100000F</c>.
+/// </summary>
+/// <remarks>
+/// Faithful port of <c>gmSmartBoxUI::RecvNotice_SetFramerateDisplay @ 0x004D65E0</c>,
+/// <c>gmSmartBoxUI::UpdateFPSMeter @ 0x004D63A0</c>, and
+/// <c>gmSmartBoxUI::UseTime @ 0x004D6E30</c>. Portal string table 0x23000001,
+/// string 0x0DCFFF73 supplies the two labels <c>FPS:</c> and <c>DEG:</c>;
+/// retail inserts both floating-point values with two decimal places.
+/// </remarks>
+public sealed class RetailFpsController
+{
+    public const uint LayoutId = 0x2100000Fu;
+    public const uint DisplayElementId = 0x10000047u;
+
+    private readonly UiText _display;
+    private readonly Func<double> _framesPerSecond;
+    private readonly Func<double> _degradeMultiplier;
+    private readonly Func<bool> _isVisible;
+
+    private RetailFpsController(
+        UiText display,
+        Func<double> framesPerSecond,
+        Func<double> degradeMultiplier,
+        Func<bool> isVisible)
+    {
+        _display = display;
+        _framesPerSecond = framesPerSecond;
+        _degradeMultiplier = degradeMultiplier;
+        _isVisible = isVisible;
+
+        // The selected catalog element is authored at (1,1) inside gmSmartBoxUI.
+        // Selective LayoutDesc import makes it a root, so restore that parent-relative
+        // placement explicitly instead of letting it drift to (0,0).
+        _display.Left = 1f;
+        _display.Top = 1f;
+        _display.Padding = 1f;
+        _display.Selectable = false;
+        _display.LinesProvider = BuildLines;
+        Tick();
+    }
+
+    public UiText Display => _display;
+
+    public static RetailFpsController? Bind(
+        ImportedLayout layout,
+        Func<double> framesPerSecond,
+        Func<double> degradeMultiplier,
+        Func<bool> isVisible)
+    {
+        ArgumentNullException.ThrowIfNull(layout);
+        ArgumentNullException.ThrowIfNull(framesPerSecond);
+        ArgumentNullException.ThrowIfNull(degradeMultiplier);
+        ArgumentNullException.ThrowIfNull(isVisible);
+
+        return layout.FindElement(DisplayElementId) is UiText display
+            ? new RetailFpsController(display, framesPerSecond, degradeMultiplier, isVisible)
+            : null;
+    }
+
+    /// <summary>Mirrors the retail notice-driven show/hide state each UI tick.</summary>
+    public void Tick() => _display.Visible = _isVisible();
+
+    private IReadOnlyList<UiText.Line> BuildLines()
+    {
+        string fps = _framesPerSecond().ToString("F2", CultureInfo.InvariantCulture);
+        string degrade = _degradeMultiplier().ToString("F2", CultureInfo.InvariantCulture);
+        return
+        [
+            new UiText.Line($"FPS: {fps}", _display.DefaultColor),
+            new UiText.Line($"DEG: {degrade}", _display.DefaultColor),
+        ];
+    }
+}