feat(studio): Character panel pilot — gmCharacterInfoUI report text + menu-bar picker

Task A — CharacterController (LayoutDesc 0x2100002E)
- CharacterSheet.cs: data record for all fields used by the report sections,
  with retail property-id citations per field (DateOfBirth 0x62, TotalPlayTime
  0x7d, NumDeaths 0x2b, SkillCredits 0xb5/0xc0, AugmentationStat 0x162,
  EncumbranceVal 0x5/0xe6).
- CharacterController.cs: static Bind(layout, data, datFont) wires element
  0x1000011d (m_pMainText, confirmed gmCharacterInfoUI::PostInit 0x004b86f0) as
  a UiText; LinesProvider builds the report. Report section order mirrors
  gmCharacterInfoUI::Update (0x004ba790):
  1. UpdatePlayerBirthAgeDeaths 0x004b8cb0 — birth/age/deaths
  2. UpdateEnduranceInfo 0x004b8eb0 — vitals (H/S/M cur/max)
  3. UpdateInnateAttributeInfo 0x004b87e0 — 6 attrs InqAttribute 1,2,4,3,5,6
     = Strength, Endurance, Quickness, Coordination, Focus, Self
  4. UpdateFakeSkills 0x004b8930 — skill credits (InqInt 0xb5 / 0xc0)
  5. UpdateAugmentations 0x004b9000 — aug name (InqInt 0x162 switch 1..0xb)
  6. UpdateLoad 0x004b8a20 — burden cur/max/pct
  Element 0x1000011d imports as UiText (Type 12); multi-line text set via
  LinesProvider — same pattern as ChatWindowController transcript.
- SampleData.SampleCharacter(): plausible retail-scale CharacterSheet fixture.
- FixtureProvider.Populate case 0x2100002Eu: CharacterController.Bind with
  SampleData.SampleCharacter + VitalsDatFont.
- CharacterControllerTests.cs: 10 pure data-wiring + content tests (no GL/dats).

Task B — Studio panel picker → main menu bar
- StudioWindow.OnRender: replaced the floating "Studio" toolbar window (kToolbarH
  40px) with ImGui.BeginMainMenuBar / EndMainMenuBar (kMenuBarH 22px). Panel
  picker combo now lives in the always-on-top menu bar and cannot be occluded by
  Tree/Canvas/Props panes. paneY reduced from 40→22, freeing ~18px for the canvas.

Build: dotnet build green (0 CS errors; DLL-lock warnings are AcDream.App being
live — not compile errors). Full suite: 619 passed, 2 skipped.

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

src/AcDream.App/Studio/SampleData.cs

@@ -1,3 +1,4 @@
+using AcDream.App.UI.Layout;
 using AcDream.Core.Items;
 
 namespace AcDream.App.Studio;
@@ -114,6 +115,44 @@ public static class SampleData
     public const float StaminaPct = 0.6f;
     public const float ManaPct    = 0.9f;
 
+    // ── Sample character sheet (used by CharacterController in the Studio) ───
+
+    /// <summary>
+    /// Returns a representative <see cref="CharacterSheet"/> for the studio's
+    /// synthetic character. Values are plausible retail-scale numbers so the
+    /// report renders with well-proportioned text in all sections.
+    /// </summary>
+    public static CharacterSheet SampleCharacter() => new()
+    {
+        Name       = "Studio Player",
+        Level      = 126,
+        Race       = "Aluvian",
+        Heritage   = "Aluvian Heritage",
+        Title      = "the Adventurer",
+        BirthDate  = "January 5, 2001",
+        PlayTime   = "2 years, 114 days, 4 hours",
+        Deaths     = 42,
+
+        HealthCurrent  = 80,   HealthMax  = 100,
+        StaminaCurrent = 60,   StaminaMax = 100,
+        ManaCurrent    = 90,   ManaMax    = 100,
+
+        Strength     = 100,
+        Endurance    = 100,
+        Quickness    = 100,
+        Coordination = 100,
+        Focus        = 100,
+        Self         = 100,
+
+        UnspentSkillCredits     = 12,
+        SpecializedSkillCredits = 4,
+
+        AugmentationName = "Swords",
+
+        BurdenCurrent = 1200,
+        BurdenMax     = 4500,
+    };
+
     // ── Helpers ─────────────────────────────────────────────────────────────
 
     private static void AddItem(