feat(studio): Attributes tab Pass 2 — click-to-select (highlight + footer B + raise triangles) + tab states

- UiClickablePanel: new UiPanel subclass with OnClick action + HandlesClick=true
  so row clicks survive whole-window-Draggable ancestor frames.

- CharacterStatController overhaul (Pass 2):
  - Tab bar button states: SetButtonStateRecursive walks each tab group container
    (0x10000228/229/538) setting UiButton.ActiveState="Open" (Attributes) or
    "Closed" (Skills/Titles) via UIStateId enum string names from DatReaderWriter.
  - Row click: 9 rows become UiClickablePanel; sel[] mutable box drives footer/highlight.
  - Toggle: clicking the same row deselects (→ footer State A); click a new row
    updates title="Attrib: value", line-1 label="Experience To Raise:", line-1
    value=cost, line-2="Unassigned Experience:" in both states.
  - Row highlight: BackgroundColor=HighlightBg (semi-translucent gold) on selected row.
  - Raise buttons (0x10000246 ×1 + 0x100005EB ×10): hidden initially; shown on
    selection with ActiveState="Normal" (affordable) or "Ghosted" (cost=0 or unaffordable).
    CollectButtonsById tree-walk finds ALL copies of the button across tab-page mounts
    (not just the last-registered _byId copy) so all instances are controlled.

- CharacterSheet: AttributeRaiseCosts long[] (Strength…Mana raise costs in retail
  display order; cost=0 → max/disabled row demos the Ghosted button state).
- SampleData.SampleCharacter: fills AttributeRaiseCosts[9] — Strength/Quickness=0
  (maxed), Focus@10→110 matching the retail screenshot (spec §4).

- 35 new tests (total 673 pass) covering: row click→footer B title/line1/line2,
  toggle deselect→footer A, switch row, highlight set/clear, raise button
  hidden/Normal/Ghosted/deselect, tab Open/Closed states, GetRaiseCost helper,
  GetRowName helper, SampleData fixture sanity.

Console.WriteLine("[CharacterStat] Row click: index=N → selected=N (Name)") fires
on every click for the user's live verification in the studio.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/AcDream.App/UI/UiPanel.cs

@@ -1,3 +1,4 @@
+using System;
 using System.Numerics;
 
 namespace AcDream.App.UI;
@@ -94,3 +95,43 @@ public class UiSimpleButton : UiPanel
         ctx.DrawString(Text, tx, ty, TextColor);
     }
 }
+
+/// <summary>
+/// A <see cref="UiPanel"/> that fires an <see cref="OnClick"/> callback when the user
+/// left-clicks it. Used for the attribute-list rows in the Character window — each row
+/// is a transparent container that needs to respond to pointer hits while its children
+/// (icon, name, value) are ClickThrough decorations.
+///
+/// <para>Retail analog: the <c>AttributeInfoRegion</c> row widget in <c>gmAttributeUI</c>
+/// catches <c>UIEvent_LeftClick</c> (0x01) and calls <c>SetSelectedAttribute</c> on the
+/// parent window. In acdream we wire the equivalent via this action callback instead of
+/// the retail message bus.</para>
+/// </summary>
+public class UiClickablePanel : UiPanel
+{
+    /// <summary>Called when the user releases the left mouse button over this panel.</summary>
+    public Action? OnClick { get; set; }
+
+    public UiClickablePanel()
+    {
+        // Rows must receive pointer events — override the UiPanel default (ClickThrough=false,
+        // which is the UiElement base default).  Explicit for clarity.
+        ClickThrough = false;
+    }
+
+    /// <summary>HandlesClick = true ensures this row receives its own Click even when
+    /// it is nested inside a Draggable ancestor window frame (e.g. the future character
+    /// window with a whole-window drag handle). Without this, the press would be consumed
+    /// by the ancestor's drag logic and the Click would never fire.</summary>
+    public override bool HandlesClick => true;
+
+    public override bool OnEvent(in UiEvent e)
+    {
+        if (e.Type == UiEventType.Click && Enabled)
+        {
+            OnClick?.Invoke();
+            return true;
+        }
+        return false;
+    }
+}