Restore ChangeBiome claim flag

[777Ricky]

Summary

• Restore the claim-only ChangeBiome flag using current biome registries
• Restore command integration, permission-filtered tab completion, messages, and registration
• Reapply the selected biome after claim resizing
• Restore the parent claim's biome when deleting a subdivision

Why

ChangeBiome was removed during the 1.21.11 update, but servers/players still rely on claim-scoped biome customization.

Notes

• Biome updates are scheduled across ticks to limit per-tick work
• Claim bounds are applied inclusively through World#getMaxHeight() - 1
• Top-level claim deletion does not attempt seed-biome restoration because Bukkit does not provide a reliable API for it