feat: 新增 6 个工具并重组目录结构

新增工具:
- grep_content: 在文件内容中搜索文本/正则表达式
- get_file_info: 获取文件元信息（大小、权限、时间等）
- move_file: 移动或重命名文件/目录
- copy_file: 复制文件或目录（支持递归）
- delete_file: 删除文件或目录
- create_directory: 创建目录

目录重组:
- src/tools/shell/ - Shell 相关工具（bash）
- src/tools/filesystem/ - 文件系统工具（12个）
- 每个子目录有独立的 index.ts 导出

权限系统扩展:
- 新增操作类型: grep, info, move, copy, mkdir
- 读取类操作默认允许，写入类操作需要确认

src/tools/filesystem/copy_file.ts

@@ -0,0 +1,132 @@
+import * as fs from 'fs/promises';
+import * as path from 'path';
+import type { Tool, ToolResult } from '../../types/index.js';
+import { loadDescription } from '../load_description.js';
+import { getPermissionManager } from '../../permission/index.js';
+
+async function copyRecursive(source: string, dest: string): Promise<void> {
+  const stats = await fs.stat(source);
+
+  if (stats.isDirectory()) {
+    await fs.mkdir(dest, { recursive: true });
+    const entries = await fs.readdir(source);
+    for (const entry of entries) {
+      await copyRecursive(path.join(source, entry), path.join(dest, entry));
+    }
+  } else {
+    await fs.copyFile(source, dest);
+  }
+}
+
+export const copyFileTool: Tool = {
+  name: 'copy_file',
+  description: loadDescription('copy_file'),
+  parameters: {
+    source: {
+      type: 'string',
+      description: '源文件或目录的路径',
+      required: true,
+    },
+    destination: {
+      type: 'string',
+      description: '目标路径',
+      required: true,
+    },
+  },
+  execute: async (params: Record<string, unknown>): Promise<ToolResult> => {
+    const source = params.source as string;
+    const destination = params.destination as string;
+    const cwd = process.cwd();
+
+    const absoluteSource = path.isAbsolute(source)
+      ? source
+      : path.join(cwd, source);
+
+    const absoluteDest = path.isAbsolute(destination)
+      ? destination
+      : path.join(cwd, destination);
+
+    // 权限检查 - 源文件需要 read 权限
+    const permissionManager = getPermissionManager();
+    const sourcePermResult = await permissionManager.checkFilePermission({
+      operation: 'read',
+      path: absoluteSource,
+      workdir: cwd,
+    });
+
+    if (!sourcePermResult.allowed) {
+      if (sourcePermResult.needsConfirmation) {
+        return {
+          success: false,
+          output: '',
+          error: `需要用户确认: 读取 ${absoluteSource}\n原因: ${sourcePermResult.reason || '需要权限确认'}`,
+        };
+      }
+      return {
+        success: false,
+        output: '',
+        error: `权限被拒绝: ${sourcePermResult.reason || '不允许读取此文件'}`,
+      };
+    }
+
+    // 权限检查 - 目标位置需要 copy 权限
+    const destPermResult = await permissionManager.checkFilePermission({
+      operation: 'copy',
+      path: absoluteDest,
+      workdir: cwd,
+    });
+
+    if (!destPermResult.allowed) {
+      if (destPermResult.needsConfirmation) {
+        return {
+          success: false,
+          output: '',
+          error: `需要用户确认: 复制到 ${absoluteDest}\n原因: ${destPermResult.reason || '需要权限确认'}`,
+        };
+      }
+      return {
+        success: false,
+        output: '',
+        error: `权限被拒绝: ${destPermResult.reason || '不允许复制到此位置'}`,
+      };
+    }
+
+    try {
+      // 检查源文件是否存在
+      const sourceStats = await fs.stat(absoluteSource);
+
+      // 检查目标是否是目录
+      let finalDest = absoluteDest;
+      try {
+        const destStats = await fs.stat(absoluteDest);
+        if (destStats.isDirectory()) {
+          // 如果目标是目录，将源文件复制到该目录下
+          finalDest = path.join(absoluteDest, path.basename(absoluteSource));
+        }
+      } catch {
+        // 目标不存在，直接使用目标路径
+      }
+
+      // 确保目标目录存在
+      await fs.mkdir(path.dirname(finalDest), { recursive: true });
+
+      // 执行复制
+      if (sourceStats.isDirectory()) {
+        await copyRecursive(absoluteSource, finalDest);
+      } else {
+        await fs.copyFile(absoluteSource, finalDest);
+      }
+
+      return {
+        success: true,
+        output: `已复制: ${absoluteSource} -> ${finalDest}`,
+      };
+    } catch (error) {
+      return {
+        success: false,
+        output: '',
+        error: error instanceof Error ? error.message : String(error),
+      };
+    }
+  },
+};