feat: reject equip-slot ground item registration

Author: MikelCalvo

docs/qa/manual-client-checklist.md

@@ -294,6 +294,7 @@ Expected result:
 - valid pickup removes the ground actor, refreshes the carried inventory slot or compatible stack according to the authored stack metadata, and shows the normal pickup notice
 - a non-zero gold/elk field follows the gold-drop path regardless of the packed item position: gold decreases, the carried inventory remains unchanged, and a gold ground marker appears
 - loaded drop template metadata whose carried stack already exceeds the authored `max_count` fails closed: no ground actor, no carried-slot deletion/update, and no quickslot mutation is visible
+- if a corrupt/disposable fixture reaches the shared-world ground-handle seam with stale equipment-slot metadata on an otherwise unequipped ground snapshot, registration fails closed and no temporary ground actor becomes available
 - if a corrupt/disposable fixture has duplicate live items in the same carried cell, `ITEM_DROP` / `ITEM_DROP2` fails closed with no ground actor, no carried-slot deletion/update, no quickslot mutation, and no persisted-state mutation
 - missing, malformed, mismatched, or ground-count-over-template-`max_count` authored pickup template metadata fails closed: no item pickup notice, no inventory mutation, and the ground handle remains available for a later valid retry
 - loaded pickup template metadata marked `anti_give` or restricted by the selected character's job/sex/min-level metadata also fails closed with the bootstrap inventory-full info message and leaves the ground handle available for a later valid retry

internal/minimal/shared_world.go

@@ -916,7 +916,7 @@ func (r *sharedWorldRegistry) removeOwnedGroundItemsLocked(ownerID uint64, visib
 
 func (r *sharedWorldRegistry) RegisterGroundItem(ownerID uint64, ownerLogin string, character loginticket.Character, vid uint32, item inventory.ItemInstance) bool {
 	const maxItemGetCountCarrier = uint16(^uint8(0))
-	if item.Vnum == 0 || item.Count == 0 || item.Count > maxItemGetCountCarrier || item.Locked || item.Equipped {
+	if item.Vnum == 0 || item.Count == 0 || item.Count > maxItemGetCountCarrier || item.Locked || item.Equipped || item.EquipSlot != inventory.EquipmentSlotNone {
 		return false
 	}
 	return r.registerGroundItem(ownerID, ownerLogin, character, vid, item, 0)

internal/minimal/shared_world_test.go

@@ -348,6 +348,22 @@ func TestSharedWorldRegistryRegisterGroundItemRejectsEquippedItem(t *testing.T)
 	}
 }
 
+func TestSharedWorldRegistryRegisterGroundItemRejectsUnequippedItemWithEquipSlot(t *testing.T) {
+	registry := newSharedWorldRegistry()
+	owner := peerVisibilityCharacter("EquipSlotGroundOwner", 0x0103019d, 0x0204019d, 1200, 2200, 0, 101, 201)
+	ownerID, _ := registry.Join(owner, newPendingServerFrames(), nil)
+	if ownerID == 0 {
+		t.Fatal("expected equip-slot ground-item owner join to allocate a shared-world entity id")
+	}
+
+	if registry.RegisterGroundItem(ownerID, "equip-slot-ground-owner", owner, 0x07000014, inventory.ItemInstance{Vnum: 3001, Count: 1, EquipSlot: inventory.EquipmentSlotWeapon}) {
+		t.Fatal("expected unequipped ground item with equip slot metadata to fail closed")
+	}
+	if registry.GroundItemExists(0x07000014) {
+		t.Fatal("expected rejected equip-slot ground item to stay absent")
+	}
+}
+
 func TestSharedWorldRegistryRegisterGroundItemRejectsZeroVID(t *testing.T) {
 	registry := newSharedWorldRegistry()
 	owner := peerVisibilityCharacter("ZeroVIDDropOwner", 0x0103019a, 0x0204019a, 1200, 2200, 0, 101, 201)

spec/protocol/item-drop-pickup-bootstrap.md

@@ -139,7 +139,7 @@ The first gold-drop runtime slice owns the gold amount fields on `CG::ITEM_DROP`
 
 For the first visible-peer pickup runtime slice, accepted pickup is visible-world scoped:
 
-1. Accepted drops are registered as temporary bootstrap ground handles at the dropper's current effective map/position after the selected character mutation is persisted; zero-HP/dead owners, locked item snapshots, and snapshots still marked equipped are rejected at the shared-world ground-handle seam so death-state races or stale lock/equipment-state snapshots cannot create new visible handles.
+1. Accepted drops are registered as temporary bootstrap ground handles at the dropper's current effective map/position after the selected character mutation is persisted; zero-HP/dead owners, locked item snapshots, snapshots still marked equipped, and unequipped snapshots that still carry authored equipment-slot metadata are rejected at the shared-world ground-handle seam so death-state races or stale lock/equipment-state snapshots cannot create new visible handles.
 2. The dropper receives the same direct `GC::ITEM_GROUND_ADD` + `GC::ITEM_OWNERSHIP` already owned by the first drop slice, currently visible living peers receive one queued add/ownership pair for the same handle, and later visible sessions that enter `GAME` while the handle remains pending receive that same add/ownership pair after self bootstrap, peer-player bootstrap, and visible static-actor bootstrap frames. Zero-HP/dead peers stay registered for their own restart/teardown flow, but they are skipped as recipients for new ground-handle visibility fanout.
 3. `ITEM_PICKUP` is accepted when its `vid` matches a still-pending bootstrap ground handle in the collector's visible world and the collector is within the first owned pickup reach (`300` coordinate units) of the ground handle. Visible-but-out-of-reach attempts fail closed with no frames, no inventory mutation, and the temporary handle left pending.
 4. The picked ground item snapshot itself must validate as a well-formed unequipped carried item before any compatible-stack merge or fresh-slot placement is attempted. Malformed ground snapshots, including stale snapshots that still carry an authored equipment slot while not marked equipped or snapshots still marked `equipped`, fail closed before recipient inventory mutation, pickup notice, persistence, or temporary ground-handle removal.