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/state/struggle/StruggleState.java

@@ -212,16 +212,6 @@ public abstract class StruggleState {
      */
     protected abstract boolean canStruggle(PlayerBindState state);
 
-    /**
-     * Check if the item being struggled against is locked.
-     *
-     * @param state The player's bind state
-     * @return true if the item is locked
-     */
-    protected boolean isItemLocked(PlayerBindState state) {
-        return false; // Default: not locked, subclasses override
-    }
-
     /**
      * Check if debug logging is enabled.
      *