feat: v3.6 重构 - 拆分 ai_cli.py 为模块化架构

本次更新由 mimo 自动化执行，与开发者无关。
新增 xiaoli/ 包:
- __main__.py: 入口点 (python -m xiaoli)
- app.py: 主应用薄编排层（~400行 vs 原3860行）
- config.py: 配置管理
- engines.py: AI 引擎管理
- sandbox.py: 代码安全沙箱
- prompt.py: 系统提示词构建
- conversation/: 对话解析器 + 历史管理
- display/: CLI/TUI 双模式输出
改进:
- 支持 argparse (--tui, --engine, --version)
- 插件命令注册表
- 更新 README
- 更新 .gitignore
原 ai_cli.py 保留向后兼容

xiaoli/sandbox.py

@@ -0,0 +1,145 @@
+"""安全代码沙箱"""
+import io
+import ast
+import re
+import time
+import threading
+import traceback
+from contextlib import redirect_stdout, redirect_stderr
+from colorama import Fore, Style
+import logging
+
+logger = logging.getLogger(__name__)
+
+DANGEROUS_MODULES = frozenset({
+    'os', 'sys', 'subprocess', 'shutil', 'socket', 'pickle',
+    'marshal', 'ctypes', 'multiprocessing', 'threading',
+    'signal', 'resource', 'posix', 'nt', 'builtins',
+    'importlib', 'code', 'codeop',
+})
+
+DANGEROUS_NAMES = frozenset({
+    'exec', 'eval', 'compile', 'execfile', 'open',
+    'globals', 'locals', 'vars', 'getattr', 'setattr',
+    'delattr', '__import__', '__builtins__', '__subclasses__',
+})
+
+DANGEROUS_PATTERNS = [
+    r'__', r'\beval\b', r'\bexec\b', r'\bcompile\b',
+    r'\bglobals\b', r'\blocals\b', r'\bgetattr\b',
+    r'\bsetattr\b', r'\b__import__\b',
+]
+
+
+class Sandbox:
+    """安全代码执行沙箱"""
+
+    def __init__(self, timeout=30, whitelist=None):
+        self.enabled = True
+        self.timeout = timeout
+        self.whitelist = whitelist or [
+            'json', 'math', 'datetime', 'random', 'collections',
+            'itertools', 'functools', 'operator', 'typing', 're'
+        ]
+        self.history = []
+
+    def is_safe(self, code: str) -> bool:
+        """快速安全检查"""
+        for pattern in DANGEROUS_PATTERNS:
+            if re.search(pattern, code, re.IGNORECASE):
+                return False
+
+        try:
+            tree = ast.parse(code)
+        except SyntaxError:
+            return False
+
+        class Checker(ast.NodeVisitor):
+            def __init__(self):
+                self.ok = True
+
+            def _check(self, name):
+                if name in DANGEROUS_NAMES or name in DANGEROUS_MODULES:
+                    self.ok = False
+
+            def visit_Import(self, node):
+                for alias in node.names:
+                    if alias.name.split('.')[0] in DANGEROUS_MODULES:
+                        self.ok = False
+                self.generic_visit(node)
+
+            def visit_ImportFrom(self, node):
+                if node.module and node.module.split('.')[0] in DANGEROUS_MODULES:
+                    self.ok = False
+                self.generic_visit(node)
+
+            def visit_Call(self, node):
+                if isinstance(node.func, ast.Name):
+                    self._check(node.func.id)
+                self.generic_visit(node)
+
+            def visit_Name(self, node):
+                self._check(node.id)
+                self.generic_visit(node)
+
+        checker = Checker()
+        checker.visit(tree)
+        return checker.ok
+
+    def run(self, code: str, variables: dict = None) -> dict:
+        """执行代码"""
+        if not self.enabled:
+            return {'success': False, 'result': '沙箱已禁用', 'stdout': '', 'stderr': '', 'time': 0}
+
+        if not self.is_safe(code):
+            return {'success': False, 'result': '代码包含危险操作', 'stdout': '', 'stderr': '', 'time': 0}
+
+        exec_vars = dict(variables or {})
+        exec_vars.update({
+            'print': print, 'len': len, 'str': str, 'int': int,
+            'float': float, 'list': list, 'dict': dict, 'tuple': tuple,
+            'set': set, 'range': range, 'enumerate': enumerate,
+            'zip': zip, 'sorted': sorted, 'sum': sum, 'max': max,
+            'min': min, 'abs': abs, 'round': round, 'type': type,
+            'isinstance': isinstance,
+        })
+
+        for mod in self.whitelist:
+            try:
+                exec_vars[mod] = __import__(mod)
+            except ImportError:
+                pass
+
+        stdout = io.StringIO()
+        stderr = io.StringIO()
+        start = time.time()
+        result = {'success': True, 'error': None, 'tb': None}
+
+        def _exec():
+            try:
+                exec(code, exec_vars)
+            except Exception as e:
+                result['success'] = False
+                result['error'] = str(e)
+                result['tb'] = traceback.format_exc()
+
+        thread = threading.Thread(target=_exec, daemon=True)
+        thread.start()
+        thread.join(timeout=self.timeout)
+        elapsed = time.time() - start
+
+        if thread.is_alive():
+            return {'success': False, 'result': f'超时 ({self.timeout}s)',
+                    'stdout': stdout.getvalue(), 'stderr': stderr.getvalue(), 'time': self.timeout}
+
+        if result['success']:
+            val = exec_vars.get('result', None)
+            return {'success': True,
+                    'result': str(val) if val is not None else '执行成功（无返回值）',
+                    'stdout': stdout.getvalue(), 'stderr': stderr.getvalue(), 'time': elapsed}
+        else:
+            return {'success': False,
+                    'result': f"错误: {result['error']}",
+                    'stdout': stdout.getvalue(),
+                    'stderr': stderr.getvalue() + '\n' + (result['tb'] or ''),
+                    'time': elapsed}