JONATHAN SAUL, JOHN IRISH, ARSHAD MOHAMMED and PARISA HAFEZI THE Israel-Hamas conflict that ended with a ceasefire on Friday showed the Palestinian group's ability to build an arsenal of homemade rockets largely with civilian materials and Iranian expertise, analysts and officials said, a feat it can likely replicate. The low cost of such arms and the need to rebuild Gaza leaves Israel and the international community with a quandary of how to meet Gazans' basic needs yet keep ordinary items such as pipes, sugar and concrete from being put to military uses. Current and former officials see no easy answers,…