feat: 新增睿美云对接模块

- 扩展 ToolConfig 配置类型，新增 external_api 类型
- 实现接口注册表，包含 90+ 睿美云开放接口定义
- 实现 TPOS SHA256WithRSA 签名鉴权
- 实现睿美云 API 客户端，支持多租户配置
- 新增代理路由 /api/ruimeiyun/call/{api_name}
- 支持接口权限控制和健康检查

backend/app/routers/tool_configs.py

@@ -354,7 +354,8 @@ async def get_config_types():
             {"code": "datasource", "name": "数据源配置", "description": "数据库连接等"},
             {"code": "jssdk", "name": "JS-SDK 配置", "description": "企微侧边栏等"},
             {"code": "webhook", "name": "Webhook 配置", "description": "n8n 工作流地址等"},
-            {"code": "params", "name": "工具参数", "description": "各工具的自定义参数"}
+            {"code": "params", "name": "工具参数", "description": "各工具的自定义参数"},
+            {"code": "external_api", "name": "外部API配置", "description": "睿美云等外部系统对接"}
         ]
     }
 
@@ -387,5 +388,11 @@ async def get_config_keys():
             {"key": "default_data_tenant_id", "name": "默认数据租户ID", "encrypted": False},
             {"key": "enable_deep_thinking", "name": "启用深度思考", "encrypted": False},
             {"key": "max_history_rounds", "name": "最大历史轮数", "encrypted": False}
+        ],
+        "external_api": [
+            {"key": "ruimeiyun_base_url", "name": "睿美云 API 地址", "encrypted": False},
+            {"key": "ruimeiyun_account", "name": "睿美云 TPOS 账号", "encrypted": False},
+            {"key": "ruimeiyun_private_key", "name": "睿美云 RSA 私钥", "encrypted": True},
+            {"key": "ruimeiyun_allowed_apis", "name": "允许的接口列表(JSON)", "encrypted": False}
         ]
     }