[chestshop] Remove AuthMe, BlockLocker, Heroes, LWC, LockettePro, RedProtect integrations

Drop support for six third-party plugin integrations the fork no longer needs, shrinking the Bukkit-event coupling surface (a step toward replacing the event-driven internals with an API). Kept: WorldGuard, GriefPrevention, ItemBridge, ShowItem.

Removed: plugins/{AuthMe,BlockLocker,Heroes,LockettePro,RedProtectBuilding,LightweightChestProtection}.java; their Dependency enum entries + loadPlugin switch cases; the AuthMe import in ChestShop.java; the LWC/AuthMe/Heroes/RedProtect config (10 @ConfigurationValue + Properties fields + applyFrom lines + config.yml keys); the 3 LWC-only messages (PROTECTED_SHOP, PROTECTED_SHOP_SIGN, NOT_ENOUGH_PROTECTIONS); the 6 plugin.yml softdepends; and the 7 compileOnly vendored deps (heroes, authme, LWCX, redprotect x2, blocklocker, lockettepro).

Kept TURN_OFF_DEFAULT_PROTECTION_WHEN_PROTECTED_EXTERNALLY and the ProtectionCheckEvent/BuildPermissionEvent (still used by WorldGuard/GriefPrevention). Security.protect() is now orphaned (was LWC-only) — left in place.