BountyBags

## Added
- Added Dragon Bounty Bag.
- Added Warden Bounty Bag.
- Added Wither Bounty Bag.
- Added separate boss drop chances for the Ender Dragon, Warden, and Wither.
- Added dedicated configurable boss loot pools: `dragon_loot`, `warden_loot`, and `wither_loot`.
- Added boss loot pool configuration for loot items, minimum item count, maximum item count, and item weight/drop chance.
- Added the `boss_mob_drops` config section.
- Added boss bags to the custom Bounty Bags creative tab.
- Added a separate boss drop system so boss bag drops do not interfere with regular mob bag drop rates.
- Added built-in boss handling for Ender Dragon, Warden, and Wither to preserve boss bag drops even with older configs.

## Changed
- Changed the default Ender Dragon boss bag drop chance to `0.50`.
- Changed the default Warden boss bag drop chance to `0.50`.
- Changed the default Wither boss bag drop chance to `0.25`.
- Changed the default value of `useCustomLoot` to `true`.
- Updated the common config flow so the generated live config is `config/bountybags-common.toml`.

## Fixed
- Fixed Epic bag rarity tooltip color so Epic bags now appear purple instead of blue.
- Restored full configurable custom loot support for all bag tiers, including boss bags.
- Restored config-driven recycling ratio support to match Forge behavior.