XP System

• Adds a lightweight XP/level component to every player and keeps a top-left HUD with current level, XP, and percentage to the next level.
• Earn XP by breaking blocks (extra for ores/gems), crafting recipes (scales with output count), and killing entities (larger rewards for player kills).
• Leveling curve starts at 75 XP for level 2 and grows by 35 XP per level; level-ups trigger an on-screen message.
• The HUD updates automatically as XP changes; no commands are required.

Notes & Suggestions

• Progress is stored on the player entity only; it will reset if the server is wiped or the entity data is cleared. Persisting to disk or config would make progress durable across resets.
• You can extend rewards to more activities or make values configurable if you want finer tuning for your server.