feat(agents): 添加 Agent 预设管理功能

- 创建 Server Agents API 路由 (CRUD + presets + defaults)
- 添加 UI Agent 类型定义和 API 客户端函数
- 实现 AgentsPanel 组件 (预设/自定义 Agent 列表)
- 实现 AgentEditor 组件 (创建/编辑 Agent)
- 实现 AgentDefaultsEditor 组件 (全局默认配置)
- 集成 AgentsPanel 到 Web 和 Desktop 应用

packages/web/src/pages/Chat.tsx

@@ -3,7 +3,7 @@
  */
 
 import { useEffect, useRef } from 'react';
-import { WifiOff, MessageSquare, Settings, FolderOpen, Terminal, Plug, Zap } from 'lucide-react';
+import { WifiOff, MessageSquare, Settings, FolderOpen, Terminal, Plug, Zap, Bot } from 'lucide-react';
 import { motion, AnimatePresence } from 'framer-motion';
 import {
   useChat,
@@ -25,6 +25,7 @@ interface ChatPageProps {
   onOpenCommands?: () => void;
   onOpenMCP?: () => void;
   onOpenHooks?: () => void;
+  onOpenAgents?: () => void;
 }
 
 export function ChatPage({
@@ -38,6 +39,7 @@ export function ChatPage({
   onOpenCommands,
   onOpenMCP,
   onOpenHooks,
+  onOpenAgents,
 }: ChatPageProps) {
   const {
     messages,
@@ -132,8 +134,21 @@ export function ChatPage({
           <ConnectionStatus />
 
           {/* 工具栏按钮 */}
-          {(onOpenConfig || onToggleFileBrowser || onOpenCommands || onOpenMCP || onOpenHooks) && (
+          {(onOpenConfig || onToggleFileBrowser || onOpenCommands || onOpenMCP || onOpenHooks || onOpenAgents) && (
             <div className="flex items-center gap-1.5 border-l border-gray-600 pl-3">
+              {/* Agents 按钮 */}
+              {onOpenAgents && (
+                <motion.button
+                  whileHover={{ scale: 1.1 }}
+                  whileTap={{ scale: 0.9 }}
+                  onClick={onOpenAgents}
+                  className="p-1.5 rounded-lg text-gray-400 hover:text-gray-200 hover:bg-gray-700 transition-colors"
+                  title="Agent Presets"
+                >
+                  <Bot size={20} />
+                </motion.button>
+              )}
+
               {/* Hooks 按钮 */}
               {onOpenHooks && (
                 <motion.button