Develop a Spigot/Paper Minecraft plugin that implements a global material-locking system controlled by the command /am everyone set <tier> <true/false>, covering Leather, Chain, Copper, Iron, Diamond, and Netherite. The plugin must strictly enforce these tiers by cancelling CraftItemEvent for locked recipes, clearing restricted items from EntityDeathEvent to prevent mob drops, and using InventoryClickEvent and PlayerItemHeldEvent to stop players from equipping or wielding unauthorized gear. Ensure that utility items like Flint and Steel or Shears are whitelisted for constant use, and provide a clear 'Tier Locked' message to players who attempt to use restricted materials