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/handler/MineResetHandler.java

@@ -2,14 +2,16 @@ package dev.loki.lomines.handler;
 
 import dev.loki.lomines.LoMinesPlugin;
 import dev.loki.lomines.core.Mine;
-import dev.loki.lomines.data.config.FillMode;
+import dev.loki.lomines.data.config.block.FillMode;
 import dev.loki.lomines.util.location.Cuboid;
+import dev.loki.lomines.util.location.LocationParser;
 import dev.lolib.scheduler.Scheduler;
 import net.kyori.adventure.text.Component;
 import net.kyori.adventure.text.minimessage.MiniMessage;
 import org.bukkit.Location;
 import org.bukkit.entity.Player;
 
+import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicInteger;
@@ -25,6 +27,8 @@ import java.util.concurrent.atomic.AtomicInteger;
  *   <li>Wait for all regions to complete</li>
  *   <li>Execute post-reset actions in main thread</li>
  * </ol>
+ *
+ * <p>Updated for new configuration system (v2).</p>
  */
 public final class MineResetHandler {
 
@@ -71,12 +75,20 @@ public final class MineResetHandler {
             return;
         }
 
-        if (mine.getConfig().getFillMode() == FillMode.MASK) {
-            mine.getBlockSetter().fillAtLocations(mine.getConfig().getMaskPositions(), placed ->
+        // Handle MASK fill mode
+        if (mine.getConfig().blocks().fillMode() == FillMode.MASK) {
+            List<Location> maskPositions = getMaskPositions();
+            if (maskPositions.isEmpty()) {
+                plugin.loLogger().warn("No mask positions found for mine " + mine.getName());
+                running.set(false);
+                return;
+            }
+            mine.getBlockSetter().fillAtLocations(maskPositions, placed ->
                     Scheduler.get(plugin).run(() -> onResetComplete(placed, silent)));
             return;
         }
 
+        // Handle CUBOID fill mode
         for (Cuboid region : regions) {
             mine.getBlockSetter().fill(region, blocksSet -> {
                 totalBlocks.addAndGet(blocksSet);
@@ -90,6 +102,29 @@ public final class MineResetHandler {
         }
     }
 
+    /**
+     * Gets mask positions from config.
+     */
+    private List<Location> getMaskPositions() {
+        List<Location> positions = new ArrayList<>();
+        var mask = mine.getConfig().blocks().mask();
+        if (mask == null) {
+            return positions;
+        }
+
+        for (String posStr : mask.positions().keySet()) {
+            try {
+                Location loc = LocationParser.parse(posStr);
+                if (loc != null) {
+                    positions.add(loc);
+                }
+            } catch (Exception e) {
+                plugin.loLogger().warn("Invalid mask position in mine " + mine.getName() + ": " + posStr);
+            }
+        }
+        return positions;
+    }
+
     /**
      * Called when all regions have been filled.
      * Executes post-reset actions in the main thread.
@@ -104,7 +139,7 @@ public final class MineResetHandler {
             broadcastReset();
         }
 
-        if (mine.getConfig().isTeleportOnReset()) {
+        if (mine.getConfig().teleport().enabled()) {
             teleportPlayers();
         }
 
@@ -115,7 +150,7 @@ public final class MineResetHandler {
      * Executes commands configured for reset.
      */
     private void executeResetCommands() {
-        List<String> commands = mine.getConfig().getResetCommands();
+        List<String> commands = mine.getConfig().reset().commands();
         for (String command : commands) {
             String parsed = command.replace("%mine%", mine.getName());
             plugin.getServer().dispatchCommand(plugin.getServer().getConsoleSender(), parsed);
@@ -126,7 +161,7 @@ public final class MineResetHandler {
      * Broadcasts reset message to players.
      */
     private void broadcastReset() {
-        String message = mine.getConfig().getBroadcastReset();
+        String message = mine.getConfig().reset().broadcastMessage();
         if (message != null && !message.isEmpty()) {
             String formatted = message.replace("%mine%", mine.getName());
             Component component = MiniMessage.miniMessage().deserialize(formatted);
@@ -138,8 +173,12 @@ public final class MineResetHandler {
      * Teleports players standing inside the mine to the configured location.
      */
     private void teleportPlayers() {
-        Location dest = mine.getConfig().getTeleportLocation();
-        if (dest == null || dest.getWorld() == null) {
+        var destOpt = mine.getConfig().teleport().getLocation();
+        if (destOpt.isEmpty()) {
+            return;
+        }
+        Location dest = destOpt.get();
+        if (dest.getWorld() == null) {
             return;
         }
         for (Player p : dest.getWorld().getPlayers()) {