Adds a mute-villager-sound option to silence managed villagers' idle/trade noise, plus explosion and save-crash fixes.

Added

• mute-villager-sound config option — set true to mute managed villagers' "hmm"/trade sounds.

Fixes

• Managed villagers no longer get shoved out of place by creeper/TNT explosions.
• Fixed a crash saving villagers with large trade lists (UTFDataFormatException). 2.1.0 villagers still load fine.
• Folia: skip the shutdown save loop that could trip thread violations; auto-save still persists everything.