fix(ui): port retail item drag visuals

Keep retail's underlay-free m_pDragIcon separate from the full cell icon and reveal the authored ghost mesh on physical source cells for the complete drag lifecycle. This removes the backpack backing from the cursor and retires AP-47.

Co-Authored-By: Codex <codex@openai.com>

docs/architecture/retail-divergence-register.md

@@ -155,7 +155,6 @@ AP-94..AP-112 for the confirmed retail-UI completion gaps.
 | AP-41 | Scrollbar thumb 3-slice cap fallback only: single-tile draw (`0x06004C63`) used only when `ThumbTopSprite`/`ThumbBotSprite` are unset; the chat controller passes all three cap ids so the 3-slice path is drawn in practice | `src/AcDream.App/UI/UiScrollbar.cs:35` | The fallback single-tile path is unreachable when caps are bound (chat controller always sets them); the 3-slice path is the active code path | Only if a future caller omits the cap ids will the fallback fire — no visual regression in the chat window | `UIElement_Scrollbar::UpdateLayout @0x4710d0`; cap sprites `0x06004C60` (top) + `0x06004C66` (bottom) from base layout `0x2100003E` |
 | AP-42 | `UiMenu` item model is flat (label + opaque payload, single-level popup); retail `UIElement_Menu::MakePopup @0x46d310` supports hierarchical nested submenus via recursive popup chain | `src/AcDream.App/UI/UiMenu.cs` | The chat talk-focus menu is single-level (14 rows, 2 columns, no submenu); hierarchy is latent and unreachable through the chat window — no behavioral difference in the current usage | A future menu with nested submenus would render flat (only the top-level items drawn, no drill-down) | `UIElement_Menu::MakePopup` @0x46d310 |
 | AP-45 | `PublicUpdatePropertyInt (0x02CE)` sequence byte parsed-past but not honored; last update wins (no freshness check against sequence number) | `src/AcDream.Core.Net/Messages/PublicUpdatePropertyInt.cs` | Loopback ACE rarely reorders; latest-wins matches `PrivateUpdateVital`/`UpdatePosition`'s existing non-sequence behavior. Sequence tracking added when needed alongside TS-26. | A reordered 0x02CE on a real network could apply a stale UiEffects value — item icon temporarily shows the wrong effect state, corrected on next update | `PublicUpdatePropertyInt` sequence byte (ACE GameMessagePublicUpdatePropertyInt) |
-| AP-47 | Cursor drag ghost reuses the full composited `m_pIcon` (incl. type-default underlay) instead of retail's dedicated `m_pDragIcon` (base + custom-overlay, NO type-default underlay). Opacity now matches retail (full). | `src/AcDream.App/UI/UiRoot.cs` (`DrawDragGhost`/`GhostAlpha`) → `src/AcDream.App/UI/UiItemSlot.cs` (`GetDragGhost`) | Cosmetic only — the dragged item is still unambiguously identifiable; building the second underlay-less composite is deferred polish; the ghost is item-agnostic in UiRoot via `GetDragGhost()` | The ghost carries the opaque type-default underlay backing rather than retail's underlay-less copy — a subtle look difference while dragging, no functional effect. | `IconData::RenderIcons` acclient_2013_pseudo_c.txt:407594-407625 (m_pDragIcon path); deep-dive §3.2/§5.5 |
 | AP-48 | Inventory burden reads the player's wire `EncumbranceVal` (PropertyInt 5) when present — delivered by B-Wire (login PD-bundle `UpsertProperties` + live `PrivateUpdatePropertyInt 0x02CD`); `ClientObjectTable.SumCarriedBurden` remains only as a defensive fallback for when the server omits it. | `src/AcDream.App/UI/Layout/InventoryController.cs` (`RefreshBurden`); `src/AcDream.Core.Net/ObjectTableWiring.cs` (player-int route) | B-Wire ports the retail read (`CACQualities::InqLoad` reads the server value); the client sum is now fallback-only, kept defensively. CONFIRM the server actually sends EncumbranceVal at the B-Wire visual gate, then DELETE this row. | If the server omits EncumbranceVal, the bar falls back to the client sum (the original drift) until the first 0x02CD — confirm at the gate. | `CACQualities::InqLoad` 0x0058f130; ACE PropertyInt.EncumbranceVal=5 |
 | AP-49 | Carry-capacity augmentation (PropertyInt `0xE6`) read from the player's wire property bundle when present (B-Wire PD `UpsertProperties`); defaults to 0 (correct for un-augmented characters) when absent. | `src/AcDream.App/UI/Layout/InventoryController.cs` (`RefreshBurden`) caller of `BurdenMath.EncumbranceCapacity` | B-Wire delivers the player's full PropertyInt table (incl. `0xE6` when the server sets it) via `UpsertProperties`; aug=0 is the correct no-aug default. CONFIRM the server sends `0xE6` for an augmented char at the gate, then DELETE. | An augmented character whose server omits `0xE6` reads slightly low capacity (bar fills higher than retail); un-augmented chars are exact. | `EncumbranceSystem::EncumbranceCapacity` decomp 256393 (0x004fcc00); retail `0xE6` PropertyInt augmentation |
 | AP-50 | Burden meter orientation/direction set programmatically (`Vertical=true`, `FillFromBottom=true`) rather than reading retail's `m_eDirection` property from the LayoutDesc element (property id `0x6f`). | `src/AcDream.App/UI/Layout/InventoryController.cs`; `src/AcDream.App/UI/UiMeter.cs` (`Vertical`/`FillFromBottom`) | The `m_eDirection` property is not yet read by `ElementReader`; bottom-up fill is visually confirmed against retail's burden bar art. Retire when `0x6f` is wired through `ElementReader`→`DatWidgetFactory`. | Wrong fill direction (top-down instead of bottom-up, or horizontal) if a future meter whose art requires a different direction is forced through the same code path. | `UIElement_Meter::DrawChildren` @0x46fbd0; property `0x6f` (`m_eDirection`) in the LayoutDesc |