⚡ Performance Update

Improvements:
- Fixed block break events cascading recursively during vein mining, causing severe lag on large veins
- Fixed memory leak where player UUIDs were never removed from the cooldown map on disconnect
- Optimised distance calculation now uses distanceSquared instead of distance, removing costly square root math from the mining loop
- Optimised block coordinate hashing now uses packed Long keys instead of heavy Block objects for faster vein traversal
- Optimised config values are now cached on load instead of being read from disk on every block break