Implement internationalization (i18n) system for LoRA Manager

- Added i18n support with automatic language detection based on browser settings.
- Implemented translations for English (en) and Simplified Chinese (zh-CN).
- Created utility functions for text replacement in HTML templates and JavaScript.
- Developed a comprehensive translation key structure for various application components.
- Added formatting functions for numbers, dates, and file sizes according to locale.
- Included RTL language support and dynamic updates for DOM elements.
- Created tests to verify the functionality of the i18n system.

static/js/checkpoints.js

@@ -4,6 +4,7 @@ import { createPageControls } from './components/controls/index.js';
 import { CheckpointContextMenu } from './components/ContextMenu/index.js';
 import { ModelDuplicatesManager } from './components/ModelDuplicatesManager.js';
 import { MODEL_TYPES } from './api/apiConfig.js';
+import { initializePageI18n } from './utils/i18nHelpers.js';
 
 // Initialize the Checkpoints page
 class CheckpointsPageManager {
@@ -36,6 +37,9 @@ class CheckpointsPageManager {
         // Initialize common page features
         appCore.initializePageFeatures();
         
+        // Initialize i18n for the page
+        initializePageI18n();
+        
         console.log('Checkpoints Manager initialized');
     }
 }