fix(ui): restore retail spell tabs and spellbook

Bind the spellbook and component-book tabs as their authored stateful text controls, propagate Closed/Open state into the retained DAT child tree, and keep authored label colors live across state changes.

Match retail UIElement_Text zero-margin construction so the Magic favorite captions I through VIII are no longer clipped. Add a real portal.dat spellbook fixture plus controller, state-propagation, and text-layout regression coverage.

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

src/AcDream.App/UI/UiText.cs

@@ -20,7 +20,7 @@ namespace AcDream.App.UI;
 /// Display-only text remains click-through and cannot steal focus or window drag.
 /// </para>
 /// </summary>
-public sealed class UiText : UiElement
+public sealed class UiText : UiElement, IUiDatStateful
 {
     /// <summary>Optional base-element click notice used by authored text tabs.</summary>
     public Action? OnClick { get; set; }
@@ -79,8 +79,12 @@ public sealed class UiText : UiElement
     /// <summary>Highlight colour painted behind a selected character span.</summary>
     public Vector4 SelectionColor { get; set; } = new(0.25f, 0.45f, 0.85f, 0.5f);
 
-    /// <summary>Inner text inset from the view edges, px.</summary>
-    public float Padding { get; set; } = 4f;
+    /// <summary>
+    /// Uniform inner text inset in pixels. The retail default is zero:
+    /// <c>UIElement_Text::UIElement_Text @ 0x00468570</c> clears all four margins
+    /// before applying any authored margin properties.
+    /// </summary>
+    public float Padding { get; set; }
 
     /// <summary>Retail property 0x20. Independent of horizontal/vertical
     /// justification; false permits the normal multi-line layout path.</summary>
@@ -156,7 +160,11 @@ public sealed class UiText : UiElement
     private UiDatFont? _lastDatFont;
     private float _lastLineHeight = 16f;
     private float _lastBaseY;          // top Y of line 0 in local space
-    private float _lastPadding = 4f;
+    private float _lastPadding;
+
+    private ElementInfo? _datInfo;
+    private uint _activeRetailStateId = UiStateInfo.DirectStateId;
+    private string _activeDatStateName = "";
 
     // ── Selection state ──────────────────────────────────────────────────
     private Pos? _selAnchor;   // where the drag started
@@ -172,9 +180,105 @@ public sealed class UiText : UiElement
         CapturesPointerDrag = false;
     }
 
-    /// <summary>The text view draws its own lines + background; any dat sub-elements
-    /// (scroll indicators, caps) are not built as separate widgets by the importer.</summary>
-    public override bool ConsumesDatChildren => true;
+    /// <summary>
+    /// Text widgets normally reproduce their own scroll/edit chrome. Retail tab text,
+    /// however, uses <c>PassToChildren</c> states whose child elements are the authored
+    /// Open/Closed cap sprites. Those children must remain in the retained tree so
+    /// <see cref="TrySetRetailState"/> can propagate the state exactly as retail does.
+    /// </summary>
+    public override bool ConsumesDatChildren
+    {
+        get
+        {
+            if (_datInfo is null) return true;
+            foreach (UiStateInfo state in _datInfo.States.Values)
+                if (state.PassToChildren)
+                    return false;
+            return true;
+        }
+    }
+
+    public uint ActiveRetailStateId => _activeRetailStateId;
+
+    public override string ActiveCursorStateName => _activeDatStateName;
+
+    internal void ConfigureDatState(ElementInfo info)
+    {
+        _datInfo = info;
+        _activeRetailStateId = info.EffectiveDefaultStateId();
+        ApplyDatState(_activeRetailStateId, propagate: false);
+    }
+
+    public bool TrySetRetailState(uint stateId)
+        => ApplyDatState(stateId, propagate: true);
+
+    private bool ApplyDatState(uint stateId, bool propagate)
+    {
+        if (_datInfo is null) return false;
+
+        UiStateInfo? state = null;
+        string stateName;
+        if (stateId == UiStateInfo.DirectStateId)
+        {
+            if (!_datInfo.States.TryGetValue(stateId, out state)
+                && !_datInfo.StateMedia.ContainsKey(""))
+                return false;
+            stateName = "";
+        }
+        else if (_datInfo.States.TryGetValue(stateId, out state))
+        {
+            stateName = state.Name;
+        }
+        else
+        {
+            stateName = UiButtonStateMachine.StateName(stateId);
+            if (string.IsNullOrEmpty(stateName))
+                stateName = RetailUiStateIds.StateName(stateId);
+            if (string.IsNullOrEmpty(stateName)
+                || !_datInfo.StateMedia.ContainsKey(stateName))
+                return false;
+        }
+
+        _activeRetailStateId = stateId;
+        _activeDatStateName = stateName;
+        BackgroundSprite = _datInfo.StateMedia.TryGetValue(stateName, out var media)
+            ? media.File
+            : _datInfo.StateMedia.TryGetValue("", out var direct) ? direct.File : 0u;
+
+        if (_datInfo.TryGetEffectiveProperty(0x1Bu, out UiPropertyValue color, stateId)
+            && TryColor(color, out Vector4 resolvedColor))
+            DefaultColor = resolvedColor;
+
+        if (propagate && state?.PassToChildren == true)
+        {
+            foreach (UiElement child in Children)
+                if (child is IUiDatStateful stateful)
+                    stateful.TrySetRetailState(stateId);
+        }
+
+        return true;
+    }
+
+    private static bool TryColor(UiPropertyValue property, out Vector4 color)
+    {
+        UiPropertyValue? value = property.Kind == UiPropertyKind.Color
+            ? property
+            : property.Kind == UiPropertyKind.Array
+                && property.ArrayValue.Count > 0
+                && property.ArrayValue[0].Kind == UiPropertyKind.Color
+                    ? property.ArrayValue[0]
+                    : null;
+        if (value is null)
+        {
+            color = default;
+            return false;
+        }
+
+        UiColorValue c = value.ColorValue;
+        float alpha = c.Alpha == 0 ? 1f : c.Alpha / 255f;
+        color = new Vector4(c.Red / 255f, c.Green / 255f, c.Blue / 255f, alpha);
+        return true;
+    }
 
     /// <summary>
     /// Clamp a scroll offset to [0, max] where max = content-height - view-height