chore: initial commit - LoMines v3.0.0 base structure

- Java rewrite from Kotlin
- LoAPI 3.0.0 integration
- Paper 1.21 support
- Core mine system with handlers
- BlockSetter abstraction (Bukkit/Oraxen/ItemsAdder)
- Statistics and leaderboard system
- Group wand for batch mine creation
- Mask fill mode support

Known issues:
- ConfigLoader.java: 712 lines (needs refactoring)
- MineCommands.java: 341 lines (needs splitting)
- 7 classes exceed 200 line limit
- Code quality improvements needed (KISS, DRY, SOLID)

src/main/java/com/loki/lomines/handler/MineRewardHandler.java

@@ -0,0 +1,71 @@
+package com.loki.lomines.handler;
+
+import com.loki.lomines.LoMinesPlugin;
+import com.loki.lomines.data.MineConfig;
+import com.loki.lomines.data.Reward;
+import org.bukkit.Material;
+import org.bukkit.block.Block;
+import org.bukkit.entity.Player;
+import org.bukkit.inventory.ItemStack;
+
+import java.util.List;
+import java.util.Random;
+
+/**
+ * Handles reward distribution for block breaks in mines.
+ * Checks configured rewards and gives items/executes commands based on chance.
+ */
+public final class MineRewardHandler {
+    
+    private final List<Reward> rewards;
+    private final LoMinesPlugin plugin;
+    private final Random random = new Random();
+    
+    public MineRewardHandler(MineConfig config, LoMinesPlugin plugin) {
+        this.rewards = config.getRewards();
+        this.plugin = plugin;
+    }
+    
+    /**
+     * Checks and applies rewards for a broken block.
+     * 
+     * @param player The player who broke the block
+     * @param block The block that was broken
+     */
+    public void checkRewards(Player player, Block block) {
+        Material material = block.getType();
+        
+        for (Reward reward : rewards) {
+            if (reward.matches(material) && rollChance(reward.getChance())) {
+                giveReward(player, reward);
+            }
+        }
+    }
+    
+    /**
+     * Rolls a random chance check.
+     * 
+     * @param chance The chance percentage (0-100)
+     * @return true if the roll succeeds
+     */
+    private boolean rollChance(double chance) {
+        return random.nextDouble() * 100.0 < chance;
+    }
+    
+    /**
+     * Gives a reward to the player.
+     * 
+     * @param player The player to give the reward to
+     * @param reward The reward to give
+     */
+    private void giveReward(Player player, Reward reward) {
+        for (ItemStack item : reward.getItems()) {
+            player.getInventory().addItem(item.clone());
+        }
+        
+        for (String command : reward.getCommands()) {
+            String parsed = command.replace("%player%", player.getName());
+            plugin.getServer().dispatchCommand(plugin.getServer().getConsoleSender(), parsed);
+        }
+    }
+}