feat: 添加搜索工具功能（Tavily Search）

- 新增 SearchToolConfig 模型：支持搜索工具配置
- Agent 增加 tools 字段：可配置可用工具列表
- 后台管理增加搜索工具配置页面
- Agent 管理增加工具启用开关
- 网页端增加搜索工具禁用复选框
- WebSocket chat 处理增加搜索调用逻辑
- 默认配置 Tavily Search API

services/agent_service.py

@@ -5,7 +5,7 @@ from sqlalchemy.orm import Session
 from typing import List, Optional, Dict
 import logging
 
-from models_v2 import Agent, LLMProvider, ChannelAgentMapping, Channel, init_default_data
+from models_v2 import Agent, LLMProvider, ChannelAgentMapping, Channel, SearchToolConfig, init_default_data
 
 logger = logging.getLogger(__name__)
 
@@ -52,6 +52,7 @@ class AgentService:
             thinking_prompt=data.get('thinking_prompt'),
             thinking_prefix=data.get('thinking_prefix', ''),
             thinking_suffix=data.get('thinking_suffix', ''),
+            tools=data.get('tools', []),  # 工具列表
             max_history=data.get('max_history', 20),
             temperature_override=data.get('temperature_override'),
             is_active=data.get('is_active', True),
@@ -405,4 +406,87 @@ class ChannelService:
             'is_active': channel.is_active,
             'is_primary': channel.is_primary,
             'agent_mappings': self.get_channel_agents(channel_id)
-        }
+        }
+
+
+class SearchToolService:
+    """搜索工具管理服务"""
+    
+    def __init__(self, db: Session):
+        self.db = db
+    
+    def get_all_configs(self) -> List[SearchToolConfig]:
+        """获取所有搜索工具配置"""
+        return self.db.query(SearchToolConfig).order_by(SearchToolConfig.is_default.desc(), SearchToolConfig.name).all()
+    
+    def get_active_configs(self) -> List[SearchToolConfig]:
+        """获取活跃的搜索工具配置"""
+        return self.db.query(SearchToolConfig).filter(SearchToolConfig.is_active == True).all()
+    
+    def get_config(self, config_id: int) -> Optional[SearchToolConfig]:
+        """获取单个配置"""
+        return self.db.query(SearchToolConfig).filter(SearchToolConfig.id == config_id).first()
+    
+    def get_default_config(self) -> Optional[SearchToolConfig]:
+        """获取默认配置"""
+        config = self.db.query(SearchToolConfig).filter(
+            SearchToolConfig.is_default == True,
+            SearchToolConfig.is_active == True
+        ).first()
+        if not config:
+            config = self.db.query(SearchToolConfig).filter(SearchToolConfig.is_active == True).first()
+        return config
+    
+    def create_config(self, data: Dict) -> SearchToolConfig:
+        """创建搜索工具配置"""
+        config = SearchToolConfig(
+            name=data.get('name'),
+            provider=data.get('provider', 'tavily'),
+            api_key=data.get('api_key'),
+            api_base=data.get('api_base'),
+            max_results=data.get('max_results', 5),
+            include_raw_content=data.get('include_raw_content', False),
+            search_depth=data.get('search_depth', 'basic'),
+            is_active=data.get('is_active', True),
+            is_default=data.get('is_default', False)
+        )
+        self.db.add(config)
+        self.db.commit()
+        self.db.refresh(config)
+        return config
+    
+    def update_config(self, config_id: int, data: Dict) -> Optional[SearchToolConfig]:
+        """更新配置"""
+        config = self.get_config(config_id)
+        if not config:
+            return None
+        
+        for key, value in data.items():
+            if hasattr(config, key) and value is not None:
+                setattr(config, key, value)
+        
+        self.db.commit()
+        self.db.refresh(config)
+        return config
+    
+    def delete_config(self, config_id: int) -> bool:
+        """删除配置"""
+        config = self.get_config(config_id)
+        if not config:
+            return False
+        
+        self.db.delete(config)
+        self.db.commit()
+        return True
+    
+    def set_default_config(self, config_id: int) -> bool:
+        """设置默认配置"""
+        self.db.query(SearchToolConfig).update({SearchToolConfig.is_default: False})
+        
+        config = self.get_config(config_id)
+        if not config:
+            return False
+        
+        config.is_default = True
+        self.db.commit()
+        return True