feat(ui): port retail item interaction policy

docs/superpowers/plans/2026-07-10-retail-ui-fidelity-completion.md

@@ -343,13 +343,25 @@ passed, 5 skipped.
 
 ### 3.2 Port item-use/drop legality into Core
 
-- [ ] Translate `ItemHolder::UseObject`, `DetermineUseResult`, and
+- [x] Translate `ItemHolder::UseObject`, `DetermineUseResult`, and
   `AttemptPlaceIn3D` to pure/testable Core policy records.
-- [ ] Include ready/busy, ownership, vendor/trade, PK/rare confirmation, stack,
+- [x] Include ready/busy, ownership, vendor/trade, PK/rare confirmation, stack,
   ground/drop, and target-type gates.
-- [ ] Keep App `ItemInteractionController` as orchestration: ask policy, show modal/
+- [x] Keep App `ItemInteractionController` as orchestration: ask policy, show modal/
   toast, send the selected wire action, and manage pending state.
 
+**Implementation (2026-07-11):** Core `ItemInteractionPolicy` is the pure port
+of all three named-retail decision trees and returns ordered typed actions (plus
+the deliberately independent placement return value). Matching-executable x86
+resolved the two damaged masks as `BF_REQUIRES_PACKSLOT (0x00800000)` and
+`BF_VENDOR (0x00000200)`. `CreateObject` now retains PWD flags and `CombatUse`;
+the App snapshot resolves component packs from portal.dat. The controller owns
+the 200 ms pre-legality throttle, ready/busy lifecycle (released by `UseDone`),
+target state, policy action dispatch, confirmation/auxiliary action seams, and
+ground-drop optimistic state. Vendor/trade/salvage/confirmation retained panels
+consume the typed action seam when those surfaces land; until then the policy
+refuses unsafe wire sends rather than bypassing their gates.
+
 ### 3.3 Add one item primary-click chokepoint
 
 - [ ] Define a controller-level activation router: target-mode acquisition first,