fix: 可选依赖改为延迟导入，支持无 tkinter/cv2 环境

- tkinter/cv2/PIL/ascii_magic 改为 try-import，服务器环境可正常运行
- TUI 相关类在 Textual 不可用时使用占位类
- 修复 TUIMainApp 继承问题

本次更新由 mimo 自动化执行，与开发者无关。

ai_cli.py

@@ -17,9 +17,21 @@ import threading
 from concurrent.futures import ThreadPoolExecutor, as_completed
 from openai import OpenAI
 from colorama import init, Fore, Style
+# tkinter 仅在视频播放功能中使用，服务器环境可能不可用
+try:
     import tkinter as tk
     from tkinter import ttk
+    TKINTER_AVAILABLE = True
+except ImportError:
+    TKINTER_AVAILABLE = False
+
+# cv2 仅在视频播放功能中使用
+try:
     import cv2
+    CV2_AVAILABLE = True
+except ImportError:
+    CV2_AVAILABLE = False
+
 import numpy as np
 from http.server import HTTPServer, BaseHTTPRequestHandler
 from urllib.parse import urlparse, parse_qs
@@ -27,8 +39,18 @@ import socket
 import webbrowser
 from datetime import datetime
 import logging
+# 图像显示相关（可选）
+try:
     from PIL import Image
+    PIL_AVAILABLE = True
+except ImportError:
+    PIL_AVAILABLE = False
+
+try:
     from ascii_magic import AsciiArt
+    ASCII_MAGIC_AVAILABLE = True
+except ImportError:
+    ASCII_MAGIC_AVAILABLE = False
 # WebSocket 服务端
 try:
     import websocket_server
@@ -68,6 +90,7 @@ except ImportError:
     print(f"{Fore.YELLOW}Textual 未安装，TUI 模式不可用。请运行: pip install textual{Style.RESET_ALL}")
 
 
+if TEXTUAL_AVAILABLE:
     class TUIBridge:
         """桥接类：让 TUI 能够调用同步的 AICLI 方法"""
 
@@ -201,23 +224,18 @@ class TUIMainApp(App):
         async def _generate_response_async(self, user_input: str) -> None:
             """异步生成响应 - 通过回调输出到 TUI"""
             try:
-            # 清除"正在思考"消息
                 self.call_after_refresh(self._clear_thinking)
 
-            # 包装回调以在主线程执行
                 def safe_output(message):
                     self.call_after_refresh(self._write_chat, message)
 
-            # 临时设置 CLI 的输出回调
                 original_callback = self.cli.tui_output_callback
                 self.cli.tui_output_callback = safe_output
 
                 try:
-                # 在线程池中运行 CLI
                     loop = asyncio.get_event_loop()
                     await loop.run_in_executor(None, self.cli.process_conversation, user_input)
                 finally:
-                # 恢复原始回调
                     self.cli.tui_output_callback = original_callback
 
                 self.call_after_refresh(self.update_status)
@@ -229,19 +247,15 @@ class TUIMainApp(App):
                 self.is_generating = False
 
         def _write_chat(self, message: str) -> None:
-        """在主线程写入聊天日志"""
             try:
                 chat_log = self.query_one("#chat-log", RichLog)
-            # RichLog 支持 ANSI 颜色代码，直接写入
                 chat_log.write(message)
             except Exception as e:
                 print(f"写入聊天失败: {e}")
 
         def _clear_thinking(self) -> None:
-        """清除'正在思考'消息"""
             try:
                 chat_log = self.query_one("#chat-log", RichLog)
-            # 移除最后一条"正在思考"消息
                 children = list(chat_log.children)
                 if children and "正在思考" in str(children[-1]):
                     chat_log.remove_child(children[-1])
@@ -252,10 +266,12 @@ class TUIMainApp(App):
             import subprocess
             import sys
             self.exit()
-        # 启动新的 CLI 进程
             subprocess.Popen([sys.executable, __file__])
-        # 退出当前进程
             os._exit(0)
+else:
+    # Textual 不可用时的占位类
+    class TUIMainApp:
+        pass
 
 
 # 配置文件路径