Villager Reforged

Villager Reforged 0.7.10+1.21.1

VR-005 reroll behavior restoration for Minecraft 1.21.1.

Changes:
- Restored the proven 0.7.5 player-facing reroll flow for active trade tables.
- Stored layout disagreements now migrate from the active source instead of refusing the reroll menu.
- Rerolls accept the active source's actual generated tier size instead of rejecting valid smaller pools.
- Only the selected tier range is replaced during a reroll; later session, payment, UI, compatibility, packaging, and metadata safeguards remain intact.