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/Layout/CharacterSheet.cs

@@ -1,3 +1,5 @@
+using System;
+
 namespace AcDream.App.UI.Layout;
 
 /// <summary>
@@ -105,6 +107,21 @@ public sealed class CharacterSheet
     /// </summary>
     public long UnassignedXp { get; init; }
 
+    // ── Attribute raise costs (ExperienceToAttributeLevel, gmAttributeUI::PostInit) ──
+    // Retail formula: ExperienceToAttributeLevel(value + 1) − ExperienceToAttributeLevel(value).
+    // We store pre-computed per-attribute costs for the fixture; cost == 0 → attribute is
+    // at max or not trainable (raise button ghosted/hidden).  Ordered to match AttrRows
+    // (Strength, Endurance, Coordination, Quickness, Focus, Self, Health, Stamina, Mana).
+    // Source: gmAttributeUI::AttributeInfoRegion::Update (0x004f1910) + CM_Train::Event_TrainAttribute.
+
+    /// <summary>
+    /// XP cost to raise each of the 9 attributes/vitals by 1, in retail display order:
+    /// [0]=Strength, [1]=Endurance, [2]=Coordination, [3]=Quickness, [4]=Focus, [5]=Self,
+    /// [6]=Health, [7]=Stamina, [8]=Mana.
+    /// Cost 0 means the attribute is at max (raise button ghosted).
+    /// </summary>
+    public long[] AttributeRaiseCosts { get; init; } = Array.Empty<long>();
+
     // ── Augmentations  (UpdateAugmentations 0x004b9000) ─────────────────────
     // Retail InqInt(0x162) = AugmentationStat; string-switch 1..0xb.