feat: 添加完整的单元测试套件

- 新增 vitest 测试框架配置
- 添加 54 个测试文件，共 951 个测试用例
- 覆盖核心模块：
  - Agent: executor, registry, config-loader, permission-merger
  - Context: manager, compaction, prune, token-counter
  - Permission: manager, bash/file/git/web checkers, wildcard
  - Session: manager, storage
  - Tools: filesystem (12个), git (10个), web, shell, todo, task
  - LSP: client, server, language
  - Utils: config, diff
  - UI: terminal

tests/unit/tools/filesystem/copy_file.test.ts

@@ -0,0 +1,173 @@
+import { describe, it, expect, beforeEach, vi } from 'vitest';
+
+// Mock fs/promises
+vi.mock('fs/promises', () => ({
+  stat: vi.fn(),
+  copyFile: vi.fn().mockResolvedValue(undefined),
+  mkdir: vi.fn().mockResolvedValue(undefined),
+  readdir: vi.fn().mockResolvedValue([]),
+}));
+
+// Mock permission manager
+vi.mock('../../../../src/permission/index.js', () => ({
+  getPermissionManager: vi.fn(() => ({
+    checkFilePermission: vi.fn().mockResolvedValue({
+      allowed: true,
+      action: 'allow',
+    }),
+  })),
+}));
+
+// Mock loadDescription
+vi.mock('../../../../src/tools/load_description.js', () => ({
+  loadDescription: vi.fn(() => '复制文件'),
+}));
+
+import { copyFileTool } from '../../../../src/tools/filesystem/copy_file.js';
+import * as fs from 'fs/promises';
+import { getPermissionManager } from '../../../../src/permission/index.js';
+
+describe('copyFileTool - 文件复制工具', () => {
+  beforeEach(() => {
+    vi.clearAllMocks();
+    vi.mocked(fs.stat).mockResolvedValue({
+      isDirectory: () => false,
+      isFile: () => true,
+    } as any);
+  });
+
+  describe('工具定义', () => {
+    it('有正确的名称', () => {
+      expect(copyFileTool.name).toBe('copy_file');
+    });
+
+    it('有正确的元数据', () => {
+      expect(copyFileTool.metadata.category).toBe('filesystem');
+      expect(copyFileTool.metadata.keywords).toContain('copy');
+      expect(copyFileTool.metadata.keywords).toContain('cp');
+    });
+
+    it('定义了必需参数', () => {
+      expect(copyFileTool.parameters.source.required).toBe(true);
+      expect(copyFileTool.parameters.destination.required).toBe(true);
+    });
+  });
+
+  describe('execute - 执行', () => {
+    it('成功复制文件', async () => {
+      // 第一次调用检查源文件，第二次调用检查目标是否是目录
+      vi.mocked(fs.stat)
+        .mockResolvedValueOnce({ isDirectory: () => false } as any)
+        .mockRejectedValueOnce(new Error('ENOENT')); // 目标不存在
+
+      const result = await copyFileTool.execute({
+        source: 'src.txt',
+        destination: 'dest.txt',
+      });
+
+      expect(result.success).toBe(true);
+      expect(result.output).toContain('已复制');
+      expect(fs.copyFile).toHaveBeenCalled();
+    });
+
+    it('复制到已存在的目录', async () => {
+      vi.mocked(fs.stat)
+        .mockResolvedValueOnce({ isDirectory: () => false } as any) // 源文件
+        .mockResolvedValueOnce({ isDirectory: () => true } as any); // 目标是目录
+
+      const result = await copyFileTool.execute({
+        source: 'file.txt',
+        destination: '/target/dir',
+      });
+
+      expect(result.success).toBe(true);
+      expect(result.output).toContain('file.txt');
+    });
+
+    it('递归复制目录', async () => {
+      vi.mocked(fs.stat)
+        .mockResolvedValueOnce({ isDirectory: () => true } as any) // 源是目录
+        .mockRejectedValueOnce(new Error('ENOENT')); // 目标不存在
+
+      vi.mocked(fs.readdir).mockResolvedValueOnce([]);
+
+      const result = await copyFileTool.execute({
+        source: 'src_dir',
+        destination: 'dest_dir',
+      });
+
+      expect(result.success).toBe(true);
+      expect(fs.mkdir).toHaveBeenCalled();
+    });
+
+    it('源文件读取权限被拒绝', async () => {
+      vi.mocked(getPermissionManager).mockReturnValue({
+        checkFilePermission: vi.fn().mockResolvedValue({
+          allowed: false,
+          action: 'deny',
+          reason: '不允许读取',
+        }),
+      } as any);
+
+      const result = await copyFileTool.execute({
+        source: '/etc/passwd',
+        destination: 'copy.txt',
+      });
+
+      expect(result.success).toBe(false);
+      expect(result.error).toContain('权限被拒绝');
+    });
+
+    it('目标位置写入权限被拒绝', async () => {
+      const mockCheck = vi.fn()
+        .mockResolvedValueOnce({ allowed: true }) // 读取权限
+        .mockResolvedValueOnce({ allowed: false, action: 'deny', reason: '不允许写入' }); // 复制权限
+
+      vi.mocked(getPermissionManager).mockReturnValue({
+        checkFilePermission: mockCheck,
+      } as any);
+
+      const result = await copyFileTool.execute({
+        source: 'src.txt',
+        destination: '/protected/dest.txt',
+      });
+
+      expect(result.success).toBe(false);
+      expect(result.error).toContain('权限被拒绝');
+    });
+
+    it('源文件需要确认', async () => {
+      vi.mocked(getPermissionManager).mockReturnValue({
+        checkFilePermission: vi.fn().mockResolvedValue({
+          allowed: false,
+          action: 'ask',
+          needsConfirmation: true,
+        }),
+      } as any);
+
+      const result = await copyFileTool.execute({
+        source: '/sensitive/file',
+        destination: 'dest.txt',
+      });
+
+      expect(result.success).toBe(false);
+      expect(result.error).toContain('需要用户确认');
+    });
+
+    it('源文件不存在返回错误', async () => {
+      vi.mocked(getPermissionManager).mockReturnValue({
+        checkFilePermission: vi.fn().mockResolvedValue({ allowed: true }),
+      } as any);
+
+      vi.mocked(fs.stat).mockRejectedValue(new Error('ENOENT: no such file'));
+
+      const result = await copyFileTool.execute({
+        source: 'nonexistent.txt',
+        destination: 'dest.txt',
+      });
+
+      expect(result.success).toBe(false);
+      expect(result.error).toContain('ENOENT');
+    });
+  });
+});