feat: 实现AI聊天页面，支持文本和语音输入、确认卡片及会话管理。

src/pages/Chat/Chat.css

@@ -108,7 +108,29 @@
     border-radius: 16px;
     font-size: 14px;
     line-height: 1.5;
-    white-space: pre-wrap;
+    word-break: break-word;
+}
+
+.chat-message-content p {
+    margin: 0;
+}
+
+.chat-message-content p+p {
+    margin-top: 8px;
+}
+
+.chat-message-content ul,
+.chat-message-content ol {
+    margin: 8px 0;
+    padding-left: 20px;
+}
+
+.chat-message-content li {
+    margin-bottom: 4px;
+}
+
+.chat-message-content strong {
+    font-weight: 600;
 }
 
 .chat-message.assistant .chat-message-content {

src/pages/Chat/Chat.tsx

@@ -1,6 +1,9 @@
 import { useState, useRef, useEffect } from 'react';
+
 import { useNavigate } from 'react-router-dom';
 import { FiArrowLeft, FiSend, FiMic, FiMicOff } from 'react-icons/fi';
+import ReactMarkdown from 'react-markdown';
+import remarkGfm from 'remark-gfm';
 import aiService from '../../services/aiService';
 import type { AIChatResponse, ConfirmationCard } from '../../types';
 import './Chat.css';
@@ -266,7 +269,11 @@ export default function Chat() {
                                     {msg.role === 'assistant' ? '🪙' : '👤'}
                                 </div>
                                 <div>
-                                    <div className="chat-message-content">{msg.content}</div>
+                                    <div className="chat-message-content">
+                                        <ReactMarkdown remarkPlugins={[remarkGfm]}>
+                                            {msg.content}
+                                        </ReactMarkdown>
+                                    </div>
 
                                     {msg.confirmationCard && (
                                         <div className="confirmation-card">