fix(ui): D.2b-B — address phase-boundary review (burden % saturation + equipped filter)

Opus phase-boundary review findings:
- I1 (faithfulness): LoadToPercent now computes from the CLAMPED fill
  (floor(LoadToFill(load)*300)), so the burden % SATURATES at 300% like retail
  (decomp 176544-176576 clamps arg2 to [0,1] BEFORE the *300). The old
  floor(load*100) over-read to 400% at 4x capacity. Golden test corrected.
- I2 (partition): exclude equipped items (CurrentlyEquippedLocation != None) from
  the contents grid + selector — a mid-session self-wield routes them through
  MoveItem(item, WielderGuid=player) into GetContents(player); retail's gm3DItemsUI
  shows pack contents only. New conformance test.
- N1: drop dead 'using System.Collections.Generic' (left after the 383e8b7 cleanup).
- N3: AP-48 risk wording (drift can be low OR high vs server EncumbranceVal).

Build green; BurdenMath 17, InventoryController/UiMeter 10 tests pass.

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

docs/architecture/retail-divergence-register.md

@@ -147,7 +147,7 @@ accepted-divergence entries (#96, #49, #50).
 | 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-46 | Health-meter gate approximation: retail shows the health meter for `IsPlayer() || pet_owner || ClientCombatSystem::ObjectIsAttackable()` (full PK/faction logic); acdream's `GameWindow.IsHealthBarTarget` uses the server PWD bits `BF_ATTACKABLE (0x10)` OR `BF_PLAYER (0x8)` | `src/AcDream.App/Rendering/GameWindow.cs` (`IsHealthBarTarget`) → `SelectedObjectController` | The PWD `BF_ATTACKABLE`/`BF_PLAYER` bits distinguish monsters + players (bar) from friendly/vendor NPCs (name-only) for the M1.5 dev loop; the pet case and the full ObjectIsAttackable PK/faction refinement (free-PK, PK-vs-PK, PKLite) are not ported | A PK/faction edge (e.g. a hostile-flagged player whose `BF_ATTACKABLE` is unset, or a pet) could show/hide the bar where retail differs — no impact on the non-PK PvE dev loop | `ClientCombatSystem::ObjectIsAttackable` acclient_2013_pseudo_c.txt:375385; `BF_ATTACKABLE` acclient.h:6437 |
 | 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 `currentBurden` summed client-side (`ClientObjectTable.SumCarriedBurden`) when the player's wire `EncumbranceVal` (PropertyInt 5) is absent; retail reads the server value via `CACQualities::InqLoad` (decomp 0x0058f130). | `src/AcDream.App/UI/Layout/InventoryController.cs` (`RefreshBurden`) | The wire `EncumbranceVal` is not yet parsed from the server; the carried-Burden sum is the nearest client-side fallback and is correct for items in the simple pack-only case. Retire when B-Wire parses PropertyInt 5. | Drift from coins/untracked items (e.g. items inside side bags that arrived before their parent, see TS-32) — burden bar reads slightly low vs retail until B-Wire lands. | `CACQualities::InqLoad` 0x0058f130; ACE PropertyInt.EncumbranceVal=5 |
+| AP-48 | Inventory burden `currentBurden` summed client-side (`ClientObjectTable.SumCarriedBurden`) when the player's wire `EncumbranceVal` (PropertyInt 5) is absent; retail reads the server value via `CACQualities::InqLoad` (decomp 0x0058f130). | `src/AcDream.App/UI/Layout/InventoryController.cs` (`RefreshBurden`) | The wire `EncumbranceVal` is not yet parsed from the server; the carried-Burden sum is the nearest client-side fallback and is correct for items in the simple pack-only case. Retire when B-Wire parses PropertyInt 5. | Drift from the server `EncumbranceVal` either way (untracked items read low; double-tracked or stale-but-present items read high) — e.g. items inside side bags that arrived before their parent (see TS-32) — until B-Wire lands. | `CACQualities::InqLoad` 0x0058f130; ACE PropertyInt.EncumbranceVal=5 |
 | AP-49 | Carry-capacity augmentation (PropertyInt `0xE6`) not tracked → `bonus=0` → un-augmented `Str×150` capacity. | `src/AcDream.App/UI/Layout/InventoryController.cs` (`RefreshBurden`) caller of `BurdenMath.EncumbranceCapacity` | PropertyInt `0xE6` is not yet parsed from the wire; aug=0 is the correct no-aug default and matches the vast majority of characters. | Augmented characters read slightly low capacity — burden bar shows slightly higher fill than retail for augmented chars; a three-aug char's cap is 150×Str higher per aug, so up to 450 extra points per point of Str. | `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 |
 | AP-51 | Main-pack `m_topContainer` cell (element `0x100001C9`) uses a placeholder/empty icon (`tex=0u`), not a weenie-driven backpack icon. | `src/AcDream.App/UI/Layout/InventoryController.cs` (`Populate`) | The player's own container entity has no item `IconId` on the client (it's a character, not an item); retail uses the equipped-pack's icon via the character's equipped-pack `CreateObject`. The equipped-pack DID path is deferred to Sub-phase C. | Main-pack cell renders blank (no icon) where retail shows the equipped backpack art — cosmetic gap visible when F12 is open. | `gmBackpackUI::PostInit` @0x4a8520 (m_topContainer bind); `CreateObject` weenie icon path |