Improve integration and migration logging

MIGRATION.md

@@ -172,6 +172,16 @@ Imported original plugins/MagicGem into MagicGem-Reforged: X files copied, Y con
 MagicGem Reforged 已启用，命令 /mgem，加载 N 颗宝石。
 ```
 
+插件还会逐项记录可选挂钩插件的状态，例如：
+
+```text
+Optional integration PlaceholderAPI: enabled (version 2.x, api=available)
+Optional integration MMOItems: absent
+Optional integration MythicMobs: enabled (version 5.x, adapter=items=..., skillApi=true)
+```
+
+迁移器也会记录开始、未找到 `plugins/MagicGem`、已完成标记跳过和迁移失败等状态。
+
 然后执行：
 
 ```text

src/main/java/cn/infstar/magicgem/MagicGemPlugin.java

@@ -27,6 +27,7 @@ import cn.infstar.magicgem.skill.SkillEngine;
 import cn.infstar.magicgem.util.MessageDispatcher;
 import de.tr7zw.changeme.nbtapi.NBT;
 import org.bukkit.command.PluginCommand;
+import org.bukkit.plugin.Plugin;
 import org.bukkit.plugin.java.JavaPlugin;
 
 import java.io.File;
@@ -90,13 +91,39 @@ public class MagicGemPlugin extends JavaPlugin {
         getServer().getPluginManager().registerEvents(gemBrowser, this);
         getServer().getPluginManager().registerEvents(guiManager, this);
         getServer().getPluginManager().registerEvents(skillEngine, this);
-        getLogger().info("Integrations: Vault=" + economy.status()
-                + ", PlayerPoints=" + points.status()
-                + ", PlaceholderAPI=" + placeholders.status()
-                + ", MythicMobs=" + mythic.status());
+        logIntegrationStatus();
         getLogger().info("MagicGem Reforged 已启用，命令 /mgem，加载 " + gemRegistry.all().size() + " 颗宝石。");
     }
 
+    private void logIntegrationStatus() {
+        logOptionalPlugin("PlaceholderAPI", "api=" + (placeholders.available() ? "available" : "unavailable"));
+        logOptionalPlugin("Vault", "economy=" + (economy.available() ? "available" : "unavailable"));
+        logOptionalPlugin("PlayerPoints", "api=" + (points.available() ? "available" : "unavailable"));
+        logOptionalPlugin("MythicMobs", "adapter=" + mythic.status());
+        logOptionalPlugin("MMOItems", null);
+        logOptionalPlugin("MythicArtifacts", null);
+        logOptionalPlugin("MythicCrucible", null);
+        logOptionalPlugin("Residence", null);
+        logOptionalPlugin("PvPManager", null);
+        logOptionalPlugin("EcoEnchants", null);
+        logOptionalPlugin("GoldenEnchants", null);
+    }
+
+    private void logOptionalPlugin(String name, String adapterStatus) {
+        Plugin dependency = getServer().getPluginManager().getPlugin(name);
+        if (dependency == null) {
+            getLogger().info("Optional integration " + name + ": absent");
+            return;
+        }
+        String version = dependency.getDescription().getVersion();
+        if (!dependency.isEnabled()) {
+            getLogger().warning("Optional integration " + name + ": present but disabled (version " + version + ")");
+            return;
+        }
+        String suffix = adapterStatus == null ? "" : ", " + adapterStatus;
+        getLogger().info("Optional integration " + name + ": enabled (version " + version + suffix + ")");
+    }
+
     public void reloadAll() {
         reloadScope("all");
     }

src/main/java/cn/infstar/magicgem/migration/LegacyDirectoryImporter.java

@@ -36,17 +36,27 @@ public final class LegacyDirectoryImporter {
 
     public ImportResult importIfPresent() {
         Path sourceDirectory = pluginsDirectory.resolve(LEGACY_PLUGIN_DIRECTORY).normalize();
-        if (targetDirectory.equals(sourceDirectory) || !Files.isDirectory(sourceDirectory)) {
+        if (targetDirectory.equals(sourceDirectory)) {
+            logger.info("MagicGem migration skipped because the legacy source and target directories are identical: "
+                    + sourceDirectory);
+            return ImportResult.none();
+        }
+        if (!Files.isDirectory(sourceDirectory)) {
+            logger.info("MagicGem migration source not found at " + sourceDirectory + "; no legacy import is needed.");
             return ImportResult.none();
         }
 
         Path marker = targetDirectory.resolve(MARKER);
-        if (Files.exists(marker)) return new ImportResult(0, 0, true);
+        if (Files.exists(marker)) {
+            logger.info("MagicGem migration already completed; skipping legacy import (marker: " + marker + ").");
+            return new ImportResult(0, 0, true);
+        }
 
         int copiedFiles = 0;
         int conflictFiles = 0;
         List<Conflict> conflicts = new ArrayList<>();
         try {
+            logger.info("Starting MagicGem migration: source=" + sourceDirectory + ", target=" + targetDirectory);
             Files.createDirectories(targetDirectory);
             for (String directory : DATA_DIRECTORIES) {
                 ImportCounts counts = importDirectory(sourceDirectory.resolve(directory),