feat: 添加MinIO文件系统支持并优化外部连接器功能

- 添加MinIO用户文件系统配置选项(BEAVER_MINIO_ROOT_USER等)
- 更新外部连接器配置结构，包括BASE_URL和认证令牌设置
- 改进connector provider支持更多类型(official, feishu_bot等)
- 实现Mistral模型推理模式支持reasoning_effort参数
- 增强外部连接器策略配置和运行时配置管理
- 添加connector bridge事件验证和安全保护机制
- 优化任务路由逻辑，区分simple_chat和new_task场景
- 更新初始技能工具提示配置，分离authoring admin功能

skills/multi-search-engine/skill.json

@@ -0,0 +1,16 @@
+{
+  "created_at": "2026-06-04T09:44:11.388282+00:00",
+  "current_version": "v0001",
+  "description": "Multi search engine integration with 16 engines (7 CN + 9 Global). Supports advanced search operators, time filters, site search, privacy engines, and WolframAlpha knowledge queries. No API keys required.",
+  "display_name": "multi-search-engine",
+  "lineage": [],
+  "name": "multi-search-engine",
+  "owners": [
+    "system",
+    "skillhub"
+  ],
+  "source_kind": "initial",
+  "status": "active",
+  "tags": [],
+  "updated_at": "2026-06-04T09:44:11.388282+00:00"
+}