feat(D.5.1): faithful toolbar slot numbers 1-9 (SetShortcutNum digit sprites, peace/war)

Port of UIElement_UIItem::SetShortcutNum (acclient_2013_pseudo_c.txt:229465) and
gmToolbarUI::RecvNotice_SetCombatMode (196610-196621). The 9 top-row toolbar slots
show digit labels 1-9 at all times (even when empty — confirmed from the user''s
retail screenshot). The digit sprites are real 32x32 PFID_A8R8G8B8 RenderSurfaces
with glyphs baked into the top-left corner (rest alpha=0), drawn Alphablend over
the slot icon/empty sprite.

Digit DID arrays (peace: property 0x10000042, war: 0x10000043) are read at startup
from LayoutDesc 0x21000037 element 0x1000034A under composite 0x10000346 using the
same ArrayBaseProperty{DataIdBaseProperty} pattern as LayoutImporter.ReadState.
A cited-constant fallback (same confirmed dat ids) is used if the dat navigation
fails. The war glyph set (darker/golden glyphs) switches on any combat stance;
peace glyphs (lighter) restore on NonCombat — re-stamped by RestampShortcutNumbers()
called from both Populate() and SetCombatMode().

Changes:
- UiItemSlot: ShortcutNum/ShortcutPeace/PeaceDigits/WarDigits state; SetShortcutNum/
  ClearShortcutNum; OnDraw restructured (no early return) so digit draws after icon.
- ToolbarController: _peaceDigits/_warDigits/_peace fields; Bind() gains peaceDigits/
  warDigits optional params; RestampShortcutNumbers() helper; Populate() and
  SetCombatMode() both call RestampShortcutNumbers().
- GameWindow: reads digit arrays under _datLock from LayoutDesc 0x21000037, passes to
  Bind(); cited constants as fallback.
- Tests: 5 new UiItemSlotTests (SetShortcutNum/ClearShortcutNum state); 4 new
  ToolbarControllerTests (top-row/bottom-row labels, peace/war switch, array injection).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

tests/AcDream.App.Tests/UI/UiItemSlotTests.cs

@@ -38,4 +38,48 @@ public class UiItemSlotTests
         Assert.Equal(0u, s.ItemId);
         Assert.Equal(0u, s.IconTexture);
     }
+
+    // ── Shortcut number tests ────────────────────────────────────────────────
+    // Port of UIElement_UIItem::SetShortcutNum (acclient_2013_pseudo_c.txt:229465).
+
+    [Fact]
+    public void ShortcutNum_defaultIsMinusOne()
+    {
+        var s = new UiItemSlot();
+        Assert.Equal(-1, s.ShortcutNum);
+    }
+
+    [Fact]
+    public void ShortcutPeace_defaultIsTrue()
+    {
+        var s = new UiItemSlot();
+        Assert.True(s.ShortcutPeace);
+    }
+
+    [Fact]
+    public void SetShortcutNum_setsIndexAndPeace()
+    {
+        var s = new UiItemSlot();
+        s.SetShortcutNum(3, peace: false);
+        Assert.Equal(3, s.ShortcutNum);
+        Assert.False(s.ShortcutPeace);
+    }
+
+    [Fact]
+    public void SetShortcutNum_peaceTrue()
+    {
+        var s = new UiItemSlot();
+        s.SetShortcutNum(0, peace: true);
+        Assert.Equal(0, s.ShortcutNum);
+        Assert.True(s.ShortcutPeace);
+    }
+
+    [Fact]
+    public void ClearShortcutNum_setsMinusOne()
+    {
+        var s = new UiItemSlot();
+        s.SetShortcutNum(5, peace: true);
+        s.ClearShortcutNum();
+        Assert.Equal(-1, s.ShortcutNum);
+    }
 }