feat: 智能体 md 产物一键发布到外部知识入库接口

- 智能体新增「入库模板名」(template_name) 配置，持久化到 config.yaml
  并经 AgentCreate/Update/Response 回读（NewAgentPage / AgentDetailPanel）
- 新增 POST /api/knowledge-ingest/publish：把 md 标题+全文发到 knowes，
  标题字段先「名称」失败再用同一 nodeName 换「标题」重试一次
- md 产物预览右上角新增「发布入库」按钮（仅智能体会话且配置了模板名时显示）

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

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

@@ -40,6 +40,7 @@ from app.gateway.routers import (
     html_page_favorites,
     intent,
     knowledge,
+    knowledge_ingest,
     llm_metrics,
     mcp,
     memory,
@@ -1341,6 +1342,9 @@ This gateway provides custom endpoints for models, MCP configuration, skills, an
     # Product knowledge base API is mounted at /api/knowledge
     app.include_router(knowledge.router)
 
+    # External knowledge-ingest (发布 md 产物到外部知识库) at /api/knowledge-ingest
+    app.include_router(knowledge_ingest.router)
+
     # System settings API is mounted at /api/system-settings
     app.include_router(system_settings.router)