Complete Chinese comment cleanup and i18n implementation

- Translate all Chinese comments to English in data-crypto.ts
- Implement proper i18n for hardcoded Chinese text in DragIndicator.tsx
- Fix remaining hardcoded Chinese in AdminSettings.tsx
- Maintain separation: code comments in English, UI text via i18n
- All Chinese comments eliminated while preserving user-facing Chinese through proper internationalization

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

src/backend/utils/data-crypto.ts

@@ -22,7 +22,7 @@ class DataCrypto {
   }
 
   /**
-   * 加密记录 - 简单直接
+   * Encrypt record - simple and direct
    */
   static encryptRecord(tableName: string, record: any, userId: string, userDataKey: Buffer): any {
     const encryptedRecord = { ...record };
@@ -74,7 +74,7 @@ class DataCrypto {
   }
 
   /**
-   * 批量解密
+   * Batch decrypt
    */
   static decryptRecords(tableName: string, records: any[], userId: string, userDataKey: Buffer): any[] {
     if (!Array.isArray(records)) return records;
@@ -82,14 +82,14 @@ class DataCrypto {
   }
 
   /**
-   * 获取用户数据密钥
+   * Get user data key
    */
   static getUserDataKey(userId: string): Buffer | null {
     return this.userCrypto.getUserDataKey(userId);
   }
 
   /**
-   * 验证用户访问权限 - 简单直接
+   * Verify user access permissions - simple and direct
    */
   static validateUserAccess(userId: string): Buffer {
     const userDataKey = this.getUserDataKey(userId);
@@ -100,7 +100,7 @@ class DataCrypto {
   }
 
   /**
-   * 便捷方法：自动获取用户密钥并加密
+   * Convenience method: automatically get user key and encrypt
    */
   static encryptRecordForUser(tableName: string, record: any, userId: string): any {
     const userDataKey = this.validateUserAccess(userId);
@@ -108,7 +108,7 @@ class DataCrypto {
   }
 
   /**
-   * 便捷方法：自动获取用户密钥并解密
+   * Convenience method: automatically get user key and decrypt
    */
   static decryptRecordForUser(tableName: string, record: any, userId: string): any {
     const userDataKey = this.validateUserAccess(userId);
@@ -116,7 +116,7 @@ class DataCrypto {
   }
 
   /**
-   * 便捷方法：批量解密
+   * Convenience method: batch decrypt
    */
   static decryptRecordsForUser(tableName: string, records: any[], userId: string): any[] {
     const userDataKey = this.validateUserAccess(userId);
@@ -124,14 +124,14 @@ class DataCrypto {
   }
 
   /**
-   * 检查用户是否可以访问数据
+   * Check if user can access data
    */
   static canUserAccessData(userId: string): boolean {
     return this.userCrypto.isUserUnlocked(userId);
   }
 
   /**
-   * 测试加密功能
+   * Test encryption functionality
    */
   static testUserEncryption(userId: string): boolean {
     try {

src/ui/Desktop/Admin/AdminSettings.tsx

@@ -839,7 +839,7 @@ export function AdminSettings({
                     <Lock className="h-4 w-4 text-green-500" />
                     <div>
                       <div className="text-sm font-medium">{t("admin.encryptionStatus")}</div>
-                      <div className="text-xs text-green-500">已启用 (v2-kek-dek)</div>
+                      <div className="text-xs text-green-500">{t("admin.encryptionEnabled")}</div>
                     </div>
                   </div>
                 </div>

src/ui/components/DragIndicator.tsx

@@ -1,5 +1,6 @@
 import React from "react";
 import { cn } from "@/lib/utils";
+import { useTranslation } from "react-i18next";
 import {
   Download,
   FileDown,
@@ -30,6 +31,8 @@ export function DragIndicator({
   error,
   className,
 }: DragIndicatorProps) {
+  const { t } = useTranslation();
+
   if (!isVisible) return null;
 
   const getIcon = () => {
@@ -54,18 +57,22 @@ export function DragIndicator({
 
   const getStatusText = () => {
     if (error) {
-      return `错误: ${error}`;
+      return t("dragIndicator.error", { error });
     }
 
     if (isDragging) {
-      return `正在拖拽${fileName ? ` ${fileName}` : ""}到桌面...`;
+      return t("dragIndicator.dragging", { fileName: fileName || "" });
     }
 
     if (isDownloading) {
-      return `正在准备拖拽${fileName ? ` ${fileName}` : ""}...`;
+      return t("dragIndicator.preparing", { fileName: fileName || "" });
     }
 
-    return `准备拖拽${fileCount > 1 ? ` ${fileCount} 个文件` : fileName ? ` ${fileName}` : ""}`;
+    if (fileCount > 1) {
+      return t("dragIndicator.readyMultiple", { count: fileCount });
+    }
+
+    return t("dragIndicator.readySingle", { fileName: fileName || "" });
   };
 
   return (
@@ -86,7 +93,7 @@ export function DragIndicator({
         <div className="flex-1 min-w-0">
           {/* Title */}
           <div className="text-sm font-medium text-foreground mb-2">
-            {fileCount > 1 ? "批量拖拽到桌面" : "拖拽到桌面"}
+            {fileCount > 1 ? t("dragIndicator.batchDrag") : t("dragIndicator.dragToDesktop")}
           </div>
 
           {/* Status text */}
@@ -127,7 +134,7 @@ export function DragIndicator({
           {isDragging && !error && (
             <div className="text-xs text-green-500 mt-2 flex items-center gap-1">
               <Download className="w-3 h-3" />
-              现在可以拖拽到桌面任意位置
+              {t("dragIndicator.canDragAnywhere")}
             </div>
           )}
         </div>