fix(desktop): console.log 清理 — 替换为结构化 logger

将 desktop/src 中 23 处 console.log 替换为 createLogger() 结构化日志:
- 生产构建自动静默 debug/info 级别
- 保留 console.error 用于关键错误可见性
- 新增 dompurify 依赖修复 XSS 防护引入缺失

涉及文件: App.tsx, offlineStore.ts, autonomy-manager.ts,
gateway-auth.ts, llm-service.ts, request-helper.ts,
security-index.ts, skill-discovery.ts, use-onboarding.ts 等 16 个文件

desktop/src/lib/security-index.ts

@@ -12,6 +12,10 @@
  * - security-utils: Input validation, XSS prevention, rate limiting
  */
 
+import { createLogger } from './logger';
+
+const log = createLogger('Security');
+
 // Re-export crypto utilities
 export {
   // Core encryption
@@ -194,7 +198,7 @@ export async function initializeSecurity(sessionId?: string): Promise<void> {
   const { initializeEncryptedChatStorage } = await import('./encrypted-chat-storage');
   await initializeEncryptedChatStorage();
 
-  console.log('[Security] All security modules initialized');
+  log.debug('All security modules initialized');
 }
 
 /**
@@ -208,7 +212,7 @@ export async function shutdownSecurity(): Promise<void> {
   const { clearKeyCache } = await import('./crypto-utils');
   clearKeyCache();
 
-  console.log('[Security] All security modules shut down');
+  log.debug('All security modules shut down');
 }
 
 /**