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/skill-discovery.ts

@@ -13,6 +13,9 @@
 
 import { intelligenceClient } from './intelligence-client';
 import { canAutoExecute } from './autonomy-manager';
+import { createLogger } from './logger';
+
+const log = createLogger('SkillDiscovery');
 
 // === Types ===
 
@@ -93,9 +96,9 @@ export class SkillDiscoveryEngine {
       this.skills = backendSkills.map(this.convertFromBackend);
       this.loadedFromBackend = true;
       this.saveIndex();
-      console.log(`[SkillDiscovery] Loaded ${this.skills.length} skills from backend`);
+      log.debug(`Loaded ${this.skills.length} skills from backend`);
     } catch (error) {
-      console.warn('[SkillDiscovery] Failed to load skills from backend:', error);
+      log.warn('Failed to load skills from backend:', error);
       // Keep using cached skills (loaded in loadIndex)
       this.loadedFromBackend = false;
     }
@@ -133,7 +136,7 @@ export class SkillDiscoveryEngine {
       this.skills = backendSkills.map(this.convertFromBackend);
       this.loadedFromBackend = true;
       this.saveIndex();
-      console.log(`[SkillDiscovery] Refreshed ${this.skills.length} skills`);
+      log.debug(`Refreshed ${this.skills.length} skills`);
       return this.skills.length;
     } catch (error) {
       console.error('[SkillDiscovery] Failed to refresh skills:', error);
@@ -335,7 +338,7 @@ export class SkillDiscoveryEngine {
     if (!options?.skipAutonomyCheck) {
       const action = installed ? 'skill_install' : 'skill_uninstall';
       const { canProceed, decision } = canAutoExecute(action, 6);
-      console.log(`[SkillDiscovery] Autonomy check for ${action}: ${decision.reason}`);
+      log.debug(`Autonomy check for ${action}: ${decision.reason}`);
 
       if (!canProceed) {
         return { success: false, reason: decision.reason };
@@ -344,7 +347,7 @@ export class SkillDiscoveryEngine {
 
     skill.installed = installed;
     this.saveIndex();
-    console.log(`[SkillDiscovery] Skill ${skillId} ${installed ? 'installed' : 'uninstalled'}`);
+    log.debug(`Skill ${skillId} ${installed ? 'installed' : 'uninstalled'}`);
     return { success: true };
   }