Add hair variants for villagers (long hair / short hair)

Currently villagers are essentially bald with hats/headscarves, and villagers of the same profession look nearly identical, making it hard for players to tell them apart.

I suggest adding two hair appearance variants on the head — one long hair and one short hair — while keeping the villagers' uniform body shape and existing profession outfits unchanged. This is purely for visual variety and does not involve the villagers' gender setting.