Add Chinese (Simplified and Traditional) localization files and implement i18n tests

- Created zh-CN.json and zh-TW.json for Simplified and Traditional Chinese translations respectively.
- Added comprehensive test suite in test_i18n.py to validate JSON structure, server-side i18n functionality, and translation completeness across multiple languages.

test_i18n.py

@@ -0,0 +1,183 @@
+#!/usr/bin/env python3
+"""
+Test script to verify the updated i18n system works correctly.
+This tests both JavaScript loading and Python server-side functionality.
+"""
+
+import os
+import sys
+import json
+import asyncio
+
+# Add the parent directory to the path so we can import the modules
+sys.path.insert(0, os.path.dirname(os.path.dirname(__file__)))
+
+def test_json_files_exist():
+    """Test that all JSON locale files exist and are valid JSON."""
+    print("Testing JSON locale files...")
+    
+    locales_dir = os.path.join(os.path.dirname(__file__), 'locales')
+    if not os.path.exists(locales_dir):
+        print("❌ Locales directory does not exist!")
+        return False
+    
+    expected_locales = ['en', 'zh-CN', 'zh-TW', 'ja', 'ru', 'de', 'fr', 'es', 'ko']
+    
+    for locale in expected_locales:
+        file_path = os.path.join(locales_dir, f'{locale}.json')
+        if not os.path.exists(file_path):
+            print(f"❌ {locale}.json does not exist!")
+            return False
+        
+        try:
+            with open(file_path, 'r', encoding='utf-8') as f:
+                data = json.load(f)
+                
+            # Check that required sections exist
+            required_sections = ['common', 'header', 'loras', 'recipes', 'modals']
+            for section in required_sections:
+                if section not in data:
+                    print(f"❌ {locale}.json missing required section: {section}")
+                    return False
+            
+            print(f"✅ {locale}.json is valid")
+            
+        except json.JSONDecodeError as e:
+            print(f"❌ {locale}.json has invalid JSON: {e}")
+            return False
+        except Exception as e:
+            print(f"❌ Error reading {locale}.json: {e}")
+            return False
+    
+    print("✅ All JSON locale files are valid")
+    return True
+
+def test_server_i18n():
+    """Test the Python server-side i18n system."""
+    print("\nTesting Python server-side i18n...")
+    
+    try:
+        from py.services.server_i18n import ServerI18nManager
+        
+        # Create a new instance to test
+        i18n = ServerI18nManager()
+        
+        # Test that translations loaded
+        available_locales = i18n.get_available_locales()
+        if not available_locales:
+            print("❌ No locales loaded in server i18n!")
+            return False
+        
+        print(f"✅ Loaded {len(available_locales)} locales: {', '.join(available_locales)}")
+        
+        # Test English translations
+        i18n.set_locale('en')
+        test_key = 'common.status.loading'
+        translation = i18n.get_translation(test_key)
+        if translation == test_key:
+            print(f"❌ Translation not found for key '{test_key}'")
+            return False
+        
+        print(f"✅ English translation for '{test_key}': '{translation}'")
+        
+        # Test Chinese translations
+        i18n.set_locale('zh-CN')
+        translation_cn = i18n.get_translation(test_key)
+        if translation_cn == test_key:
+            print(f"❌ Chinese translation not found for key '{test_key}'")
+            return False
+        
+        print(f"✅ Chinese translation for '{test_key}': '{translation_cn}'")
+        
+        # Test parameter interpolation
+        param_key = 'common.itemCount'
+        translation_with_params = i18n.get_translation(param_key, count=42)
+        if '{count}' in translation_with_params:
+            print(f"❌ Parameter interpolation failed for key '{param_key}'")
+            return False
+        
+        print(f"✅ Parameter interpolation for '{param_key}': '{translation_with_params}'")
+        
+        print("✅ Server-side i18n system working correctly")
+        return True
+        
+    except Exception as e:
+        print(f"❌ Error testing server i18n: {e}")
+        import traceback
+        traceback.print_exc()
+        return False
+
+def test_translation_completeness():
+    """Test that all languages have the same translation keys."""
+    print("\nTesting translation completeness...")
+    
+    locales_dir = os.path.join(os.path.dirname(__file__), 'locales')
+    
+    # Load English as reference
+    with open(os.path.join(locales_dir, 'en.json'), 'r', encoding='utf-8') as f:
+        en_data = json.load(f)
+    
+    def get_all_keys(data, prefix=''):
+        """Recursively get all keys from nested dictionary."""
+        keys = set()
+        for key, value in data.items():
+            full_key = f"{prefix}.{key}" if prefix else key
+            keys.add(full_key)
+            if isinstance(value, dict):
+                keys.update(get_all_keys(value, full_key))
+        return keys
+    
+    en_keys = get_all_keys(en_data)
+    print(f"English has {len(en_keys)} translation keys")
+    
+    # Check other languages
+    locales = ['zh-CN', 'zh-TW', 'ja', 'ru', 'de', 'fr', 'es', 'ko']
+    
+    for locale in locales:
+        with open(os.path.join(locales_dir, f'{locale}.json'), 'r', encoding='utf-8') as f:
+            locale_data = json.load(f)
+        
+        locale_keys = get_all_keys(locale_data)
+        
+        missing_keys = en_keys - locale_keys
+        extra_keys = locale_keys - en_keys
+        
+        if missing_keys:
+            print(f"❌ {locale} missing keys: {len(missing_keys)}")
+            # Print first few missing keys
+            for key in sorted(missing_keys)[:5]:
+                print(f"   - {key}")
+            if len(missing_keys) > 5:
+                print(f"   ... and {len(missing_keys) - 5} more")
+        
+        if extra_keys:
+            print(f"⚠️  {locale} has extra keys: {len(extra_keys)}")
+        
+        if not missing_keys and not extra_keys:
+            print(f"✅ {locale} has complete translations ({len(locale_keys)} keys)")
+    
+    return True
+
+def main():
+    """Run all tests."""
+    print("🚀 Testing updated i18n system...\n")
+    
+    success = True
+    
+    # Test JSON files
+    if not test_json_files_exist():
+        success = False
+    
+    # Test server i18n
+    if not test_server_i18n():
+        success = False
+    
+    # Test completeness
+    if not test_translation_completeness():
+        success = False
+    
+    print(f"\n{'🎉 All tests passed!' if success else '❌ Some tests failed!'}")
+    return success
+
+if __name__ == '__main__':
+    main()