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/package-info.java

@@ -0,0 +1,12 @@
+/**
+ * Handler components implementing business logic.
+ * <p>
+ * This package contains classes that handle specific aspects of mine operations:
+ * <ul>
+ *   <li>{@code MineResetHandler} - Manages mine reset operations</li>
+ *   <li>{@code MineBlockHandler} - Handles block break events in mines</li>
+ *   <li>{@code MineRewardHandler} - Manages reward distribution to players</li>
+ *   <li>{@code ActionBarHandler} - Displays information in action bar</li>
+ * </ul>
+ */
+package com.loki.lomines.handler;