refactor(core): update all classes for new config system + add tab completion

BREAKING CHANGE: Core classes updated to use new section-based config

Updated classes:
- Mine.java - uses RegionConfig, BlockConfig, new FillMode
- Mines.java - uses new ConfigLoader.ConfigLoadException
- MineFileManager.java - creates configs with new system
- MineRepository.java - uses new ConfigLoader
- MaskScanService.java - uses BlockKey for markers
- BukkitBlockSetter.java - uses Map<BlockKey, Double>

Handlers updated:
- ActionBarHandler.java - uses UIConfig with MiniMessage
- MineBlockHandler.java - uses ResetConfig
- MineRewardHandler.java - uses RewardConfig
- MineResetHandler.java - uses new config sections

Commands updated:
- MaskCommands.java - updated exception handling

Added:
- LoMinesTabCompleter.java - Bukkit tab completion for all commands
- RegistrationManager.registerTabCompleter() - registers tab completer

Removed:
- Old ConfigLoaderTest.java (uses deprecated config system)

All classes now use:
- Type-safe BlockKey instead of String
- Section-based config (region, blocks, reset, rewards, ui, teleport)
- Duration-based intervals instead of ticks
- MiniMessage formatting for action bar

src/main/java/dev/loki/lomines/LoMinesPlugin.java

@@ -42,6 +42,7 @@ public final class LoMinesPlugin extends LoPlugin {
 
             RegistrationManager registrationManager = new RegistrationManager(this);
             registrationManager.registerCommands(commandManager);
+            registrationManager.registerTabCompleter();
             registrationManager.registerListeners();
             registrationManager.initializeIntegrations(integrationManager);