feat(D-01/E): resistance & lock system rework (E1-E7)

E1: Initialize currentResistance in NBT at equip time from
    ResistanceComponent — eliminates MAX-scan fallback bug

E2: BuiltInLockComponent for organic items (already committed)

E3: canStruggle refactor — new model:
    - ARMS: always struggle-able (no lock gating)
    - Non-ARMS: only if locked OR built-in lock
    - Removed dead isItemLocked() from StruggleState + overrides

E4: canUnequip already handled by BuiltInLockComponent.blocksUnequip()
    via ComponentHolder delegation

E5: Help/assist mechanic deferred (needs UI design)

E6: Removed lock resistance from ILockable (5 methods + NBT key deleted)
    - GenericKnife: new knifeCutProgress NBT for cutting locks
    - StruggleAccessory: accessoryStruggleResistance NBT replaces lock resistance
    - PacketV2StruggleStart: uses config-based padlock resistance
    - All lock/unlock packets cleaned of initializeLockResistance/clearLockResistance

E7: Fixed 3 pre-existing bugs:
    - B2: DataDrivenItemRegistry.clear() synchronized on RELOAD_LOCK
    - B3: V2TyingPlayerTask validates heldStack before equip (prevents duplication)
    - B5: EntityKidnapperMerchant.remove() cleans playerToMerchant map (memory leak)

src/main/java/com/tiedup/remake/tasks/V2TyingPlayerTask.java

@@ -70,6 +70,13 @@ public class V2TyingPlayerTask extends TyingPlayerTask {
             targetEntity.getName().getString()
         );
 
+        // Validate heldStack hasn't changed during tying (e.g. player swapped items)
+        if (heldStack.isEmpty() || !ItemStack.isSameItemSameTags(heldStack, bind)) {
+            TiedUpMod.LOGGER.warn("[V2TyingPlayerTask] heldStack changed during tying — aborting");
+            stop();
+            return;
+        }
+
         // Equip via V2 system
         V2EquipResult result = V2EquipmentHelper.equipItem(targetEntity, bind);
         if (result.isSuccess()) {