Merge branch 'master' of http://192.168.0.200/knowledge-base-bj/deerflow-server into dhk-1

解决 artifact 预览组件冲突：mermaid 渲染(dhk-1) 与 markdown 锚点跳转(master) 取并集；package-lock.json 按 master 删除(项目用 pnpm)。

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

offline-backend-20260512/backend/app/gateway/app.py

@@ -59,6 +59,7 @@ from app.gateway.routers import (
     thread_shares,
     threads,
     uploads,
+    user_preferences,
     user_prompts,
     writing,
 )
@@ -859,6 +860,9 @@ This gateway provides custom endpoints for models, MCP configuration, skills, an
 
     app.include_router(user_prompts.router)
 
+    # Per-user UI preferences at /api/user-preferences
+    app.include_router(user_preferences.router)
+
     # Roundtable-planning drafts + recommendation history at /api/roundtable-drafts
     app.include_router(roundtable_drafts.router)