feat(ui): importer Fix C — per-element dat FontDid resolver (studio path); character level uses its retail font

DatWidgetFactory.Create now accepts an optional fontResolve: Func<uint,UiDatFont?>
parameter. When supplied and the element has a non-zero FontDid, the element
receives its own dat font instead of the shared global datFont fallback.
Null = original single-font behavior (the live GameWindow path passes null —
provably unchanged). LayoutImporter.Build/BuildFromInfos/Import all thread
the optional resolver down to the factory.

RenderStack gains a lazy font cache (ConcurrentDictionary, pre-seeded with
VitalsDatFont + LargeDatFont) and a ResolveDatFont(uint) method. StudioWindow
wires stack.ResolveDatFont into LayoutSource so every studio import gets
per-element fonts. GameWindow import calls left passing null (follow-up todo).

CharacterStatController font-hack cleanup (diagnosed via one-shot console dump
then removed):
- Name (0x10000231): dat FontDid = 18px font — remove datFont override (null)
- Heritage/PkStatus: dat FontDid = 14px fonts — remove override
- LevelCaption: dat FontDid = 16px — remove override (same font, no visual change)
- Level (0x1000023B): dat FontDid = 36px (the big retail gold font) — was forced
  to rowDatFont/LargeDatFont (18px); now drops to null so the dat 36px font drives
- TotalXpLabel/TotalXp: dat FontDid = 16px — remove override
- FooterTitle (0x1000024E): dat FontDid = 20px — remove datFont override
- KEEP: synthesized elements (XP meter overlays, 9 attribute rows, tab sprites)
  still use datFont directly since they have no dat origin

All Label/LabelTwoLine/LabelLeft/LabelProvider helpers updated: null = keep
build-time dat font; non-null = controller explicit override (backward-compat).

8 new tests in DatWidgetFactoryFontResolveTests:
- null resolver → DatFont == global datFont
- FontDid=0 → resolver not called
- resolver returns null → fallback to global datFont
- resolver called with element's FontDid
- controller DatFont override wins after build
- LayoutImporter.Build threads fontResolve to factory
- meter element fires resolver for non-zero FontDid
- BuildFromInfos without fontResolve param = original behavior

Build + all 710 App tests green.

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

src/AcDream.App/Studio/StudioWindow.cs

@@ -127,7 +127,13 @@ public sealed class StudioWindow : IDisposable
         // Load the panel described by options and add it to the UI tree.
         // Task 4b: --dump <slug> uses DumpLayout (static retail mockup, no controllers).
         // All other modes use LayoutSource + FixtureProvider (production path).
-        _source = new LayoutSource(_dats, _stack.ResolveChrome, _stack.VitalsDatFont);
+        //
+        // Fix C: pass the per-element font resolver into LayoutSource so that elements
+        // with a non-zero FontDid get their own dat font at build time.  This is wired
+        // ONLY in the studio path; GameWindow's Import calls continue to pass null so the
+        // live game path is provably unchanged (follow-up: GameWindow font-resolver wire-up).
+        _source = new LayoutSource(_dats, _stack.ResolveChrome, _stack.VitalsDatFont,
+            fontResolve: _stack.ResolveDatFont);
 
         // Resolve the dump file once (used by OnLoad + by LoadDumpPanel at runtime).
         _dumpFile = _opts.ResolveDumpFile();