feat: add chat message translation via LibreTranslate

Adds optional translation feature that shows translated chat messages
on hover in each viewer's Minecraft client language.

- TranslationService with LibreTranslate API support and caching
- Config options: enabled, endpoint, api-key
- Hover translation on chat messages in EnhancedChatRenderer
- Disabled by default, supports any LibreTranslate-compatible endpoint

src/main/java/com/loki/lochat/config/ConfigManager.java

@@ -227,6 +227,20 @@ public class ConfigManager {
         return accessor.getAnnouncementTitleDuration();
     }
 
+    // ========== Chat Translation ==========
+
+    public boolean isTranslationEnabled() {
+        return accessor.isTranslationEnabled();
+    }
+
+    public String getTranslationEndpoint() {
+        return accessor.getTranslationEndpoint();
+    }
+
+    public String getTranslationApiKey() {
+        return accessor.getTranslationApiKey();
+    }
+
     // ========== LoPreff integration ==========
 
     public boolean isLopreffEnabled() {