fix: single-click selects item and closes overlay

inventory/inventory_overlay/InventoryOverlay.gd

@@ -101,12 +101,13 @@ func _on_slot_clicked(item_id: String) -> void:
 	for child in grid.get_children():
 		if child is InventorySlot and child.item_id == item_id:
 			if _selected_slot == null:
-				_selected_slot = child
-				_drag_start_time = Time.get_ticks_msec() / 1000.0
-				_is_dragging = true
-				_create_drag_preview(child)
+				InventoryManager.select_item(item_id)
+				item_confirmed.emit(item_id)
+				hide_overlay()
 			elif _selected_slot.item_id == item_id:
-				_handle_release_same_item()
+				InventoryManager.select_item(item_id)
+				item_confirmed.emit(item_id)
+				hide_overlay()
 			else:
 				combine_requested.emit(_selected_slot.item_id, item_id)
 				_clear_selection()