feat: enhance MCP server management and system settings

- Added functionality to save MCP server configurations as templates in the MCP Manager.
- Implemented new hooks for managing system settings including Chinese response, Windows platform, and Codex CLI enhancements.
- Updated API calls to support fetching and toggling system settings.
- Introduced UI components for displaying and managing response language settings and system status.
- Enhanced error handling and notifications for server deletion and template saving actions.
- Updated localization files for new settings and descriptions in English and Chinese.

ccw/frontend/src/components/layout/Sidebar.tsx

@@ -56,6 +56,7 @@ interface NavGroupDef {
     icon: React.ElementType;
     badge?: number | string;
     badgeVariant?: 'default' | 'success' | 'warning' | 'info';
+    end?: boolean;
   }>;
 }
 
@@ -110,7 +111,7 @@ const navGroupDefinitions: NavGroupDef[] = [
     items: [
       { path: '/settings/codexlens', labelKey: 'navigation.main.codexlens', icon: Sparkles },
       { path: '/api-settings', labelKey: 'navigation.main.apiSettings', icon: Server },
-      { path: '/settings', labelKey: 'navigation.main.settings', icon: Settings },
+      { path: '/settings', labelKey: 'navigation.main.settings', icon: Settings, end: true },
       { path: '/help', labelKey: 'navigation.main.help', icon: HelpCircle },
     ],
   },