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/RetailWindowFrame.cs

@@ -0,0 +1,108 @@
+using System;
+
+namespace AcDream.App.UI.Layout;
+
+/// <summary>
+/// Mounts an imported retail window's content into the shared 8-piece beveled
+/// chrome (<see cref="UiNineSlicePanel"/>) and optionally registers it with
+/// the <see cref="UiRoot"/> window manager. This is THE mount recipe every
+/// retail window follows: frame sized content + 2×border, content inset by
+/// the border with Draggable/Resizable off (the frame owns move/resize).
+///
+/// <para>The vitals/chat/toolbar/inventory windows still inline this recipe
+/// in <c>GameWindow</c> (pre-extraction); new windows must mount through this
+/// helper instead of copying the block again — see
+/// docs/research/2026-07-02-ui-architecture-review.md (theme T1).</para>
+/// </summary>
+public static class RetailWindowFrame
+{
+    /// <summary>Per-window placement + behavior knobs. Null-valued knobs keep
+    /// the widget defaults (<see cref="UiElement"/> / <see cref="UiNineSlicePanel"/>).</summary>
+    public sealed record Options
+    {
+        /// <summary>Initial window position (screen px).</summary>
+        public float Left { get; init; }
+        public float Top { get; init; }
+
+        /// <summary>Minimum frame size; null = lock to content + 2×border (non-shrinkable).</summary>
+        public float? MinWidth { get; init; }
+        public float? MinHeight { get; init; }
+
+        /// <summary>Maximum frame height while resizing; null = unbounded.</summary>
+        public float? MaxHeight { get; init; }
+
+        /// <summary>Allow horizontal resize (frame default: true).</summary>
+        public bool ResizeX { get; init; } = true;
+
+        /// <summary>Restrict which edges start a resize; null = all edges.</summary>
+        public ResizeEdges? ResizableEdges { get; init; }
+
+        /// <summary>Window translucency (retail SetDefaultOpacity analog).</summary>
+        public float Opacity { get; init; } = 1f;
+
+        /// <summary>Start shown or hidden (hidden windows toggle via the window manager).</summary>
+        public bool Visible { get; init; } = true;
+
+        /// <summary>How the content tracks the frame when it resizes.</summary>
+        public AnchorEdges ContentAnchors { get; init; } =
+            AnchorEdges.Left | AnchorEdges.Top | AnchorEdges.Right | AnchorEdges.Bottom;
+
+        /// <summary>Force the content's ClickThrough; null = leave as imported.</summary>
+        public bool? ContentClickThrough { get; init; }
+
+        /// <summary>Register the frame under this name in the UiRoot window
+        /// manager (<see cref="WindowNames"/>); null = unmanaged window.</summary>
+        public string? WindowName { get; init; }
+    }
+
+    /// <summary>
+    /// Wrap <paramref name="content"/> (sized by the importer) in the beveled
+    /// chrome, add it to <paramref name="root"/>, and register it when
+    /// <see cref="Options.WindowName"/> is set. Returns the frame.
+    /// </summary>
+    public static UiNineSlicePanel Mount(
+        UiRoot root,
+        UiElement content,
+        Func<uint, (uint handle, int w, int h)> resolveChrome,
+        Options options)
+    {
+        ArgumentNullException.ThrowIfNull(root);
+        ArgumentNullException.ThrowIfNull(content);
+        ArgumentNullException.ThrowIfNull(resolveChrome);
+        ArgumentNullException.ThrowIfNull(options);
+
+        const int border = RetailChromeSprites.Border;
+        float contentW = content.Width;
+        float contentH = content.Height;
+
+        var frame = new UiNineSlicePanel(resolveChrome)
+        {
+            Left = options.Left,
+            Top = options.Top,
+            Width = contentW + 2 * border,
+            Height = contentH + 2 * border,
+            MinWidth = options.MinWidth ?? contentW + 2 * border,
+            MinHeight = options.MinHeight ?? contentH + 2 * border,
+            ResizeX = options.ResizeX,
+            Opacity = options.Opacity,
+            Visible = options.Visible,
+        };
+        if (options.MaxHeight is { } maxHeight) frame.MaxHeight = maxHeight;
+        if (options.ResizableEdges is { } edges) frame.ResizableEdges = edges;
+
+        content.Left = border;
+        content.Top = border;
+        content.Width = contentW;
+        content.Height = contentH;
+        content.Anchors = options.ContentAnchors;
+        if (options.ContentClickThrough is { } clickThrough) content.ClickThrough = clickThrough;
+        content.Draggable = false;   // the frame owns window move/resize
+        content.Resizable = false;
+
+        frame.AddChild(content);
+        root.AddChild(frame);
+        if (options.WindowName is { } name)
+            root.RegisterWindow(name, frame);
+        return frame;
+    }
+}