feat(ui): D.2b item interaction + retail cursors + live character sheet

Lands the codex-worktree D.2b stream plus the extraction the 2026-07-02
UI architecture review mandated before commit:

- ItemInteractionController: single owner of double-click use/equip/
  container-open, targeted-use mode (health kits), drag-out drop;
  toolbar shortcut drags don't drop the real item. ItemEquipRules for
  multi-slot (coat) coverage via equip masks.
- Cursor phase: CursorFeedbackController (semantic priority chain:
  drag > resize > window-move > target-mode > text) + RetailCursorCatalog
  (enums 0x27/0x28/0x29, hotspot 14,14; ClientUISystem::UpdateCursorState
  0x00564630) resolved through the portal EnumIDMap chain by
  RetailCursorResolver; RetailCursorManager applies dat cursor art to the
  OS cursor. Register row AP-72 covers the OS standard-cursor fallback.
- Character window goes live: CharacterSheetProvider owns sheet assembly,
  XP-curve/raise-cost math and the raise flow — extracted out of
  GameWindow per Code Structure Rule 1 instead of committing the ~430-line
  feature body there. Optimistic XP/credit debits go through eventful
  store APIs (new ClientObjectTable.UpdateInt64Property +
  LocalPlayerState.DebitIntProperty/DebitInt64Property) instead of raw
  property-dictionary writes; register row AP-73 covers the still-missing
  raise ledger (#163).
- RetailWindowFrame: the shared nine-slice window mount recipe; the
  character window uses it, remaining windows migrate via #164.
- Status-bar buttons toggle inventory/character windows; retail row-major
  backpack ordering; WorldSession.SendUseWithTarget + raise/train sends.

GameWindow shrinks 14,214 -> 13,877 lines despite the new features; the
sheet/raise logic is unit-tested in CharacterSheetProviderTests instead
of trapped in the god object. Build green; full suite 3,286 tests pass.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/AcDream.App/UI/Layout/ElementReader.cs

@@ -96,6 +96,12 @@ public sealed class ElementInfo
     /// </summary>
     public Dictionary<string, (uint File, int DrawMode)> StateMedia = new();
 
+    /// <summary>
+    /// Cursor per state: state name to (RenderSurface file id, hotspot).
+    /// The "" key represents DirectState, mirroring <see cref="StateMedia"/>.
+    /// </summary>
+    public Dictionary<string, UiCursorMedia> StateCursors = new();
+
     /// <summary>
     /// The element's initial active state name, taken from <c>ElementDesc.DefaultState.ToString()</c>.
     /// Normalized to <c>""</c> when the dat carries Undef/Undefined/0 (no default set).
@@ -160,8 +166,8 @@ public static class ElementReader
     ///     (derived placement, not the base prototype's geometry).
     ///   </description></item>
     ///   <item><description>
-    ///     <see cref="ElementInfo.StateMedia"/>: base entries are the default; derived
-    ///     entries override (or add) per state name key.
+    ///     <see cref="ElementInfo.StateMedia"/> and <see cref="ElementInfo.StateCursors"/>:
+    ///     base entries are the default; derived entries override (or add) per state name key.
     ///   </description></item>
     ///   <item><description>
     ///     <see cref="ElementInfo.Children"/>: come from the derived element's own tree only.
@@ -218,6 +224,9 @@ public static class ElementReader
         m.StateMedia = new Dictionary<string, (uint, int)>(base_.StateMedia);
         foreach (var kv in derived.StateMedia)
             m.StateMedia[kv.Key] = kv.Value;
+        m.StateCursors = new Dictionary<string, UiCursorMedia>(base_.StateCursors);
+        foreach (var kv in derived.StateCursors)
+            m.StateCursors[kv.Key] = kv.Value;
         return m;
     }
 }