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/get_file_info.test.ts

@@ -0,0 +1,188 @@
+import { describe, it, expect, beforeEach, vi } from 'vitest';
+
+// Mock fs/promises
+vi.mock('fs/promises', () => ({
+  stat: vi.fn(),
+  readlink: vi.fn(),
+  readdir: vi.fn(),
+}));
+
+// 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(() => '获取文件信息'),
+}));
+
+import { getFileInfoTool } from '../../../../src/tools/filesystem/get_file_info.js';
+import * as fs from 'fs/promises';
+import { getPermissionManager } from '../../../../src/permission/index.js';
+
+describe('getFileInfoTool - 获取文件信息工具', () => {
+  const mockStats = {
+    isDirectory: () => false,
+    isFile: () => true,
+    isSymbolicLink: () => false,
+    size: 1024,
+    mode: 0o100644,
+    birthtime: new Date('2024-01-01'),
+    mtime: new Date('2024-01-15'),
+    atime: new Date('2024-01-20'),
+    ino: 12345,
+    nlink: 1,
+  };
+
+  beforeEach(() => {
+    vi.clearAllMocks();
+    vi.mocked(fs.stat).mockResolvedValue(mockStats as any);
+  });
+
+  describe('工具定义', () => {
+    it('有正确的名称', () => {
+      expect(getFileInfoTool.name).toBe('get_file_info');
+    });
+
+    it('有正确的元数据', () => {
+      expect(getFileInfoTool.metadata.category).toBe('filesystem');
+      expect(getFileInfoTool.metadata.keywords).toContain('file');
+      expect(getFileInfoTool.metadata.keywords).toContain('info');
+      expect(getFileInfoTool.metadata.keywords).toContain('stat');
+    });
+
+    it('定义了必需的 path 参数', () => {
+      expect(getFileInfoTool.parameters.path.required).toBe(true);
+    });
+  });
+
+  describe('execute - 执行', () => {
+    it('成功获取文件信息', async () => {
+      const result = await getFileInfoTool.execute({ path: 'test.txt' });
+
+      expect(result.success).toBe(true);
+      expect(result.output).toContain('路径:');
+      expect(result.output).toContain('类型: 文件');
+      expect(result.output).toContain('大小:');
+      expect(result.output).toContain('权限:');
+      expect(result.output).toContain('创建时间:');
+      expect(result.output).toContain('修改时间:');
+      expect(result.output).toContain('inode:');
+    });
+
+    it('正确显示目录信息', async () => {
+      vi.mocked(fs.stat).mockResolvedValue({
+        ...mockStats,
+        isDirectory: () => true,
+        isFile: () => false,
+      } as any);
+      vi.mocked(fs.readdir).mockResolvedValue(['file1', 'file2', 'dir1'] as any);
+
+      const result = await getFileInfoTool.execute({ path: 'test_dir' });
+
+      expect(result.success).toBe(true);
+      expect(result.output).toContain('类型: 目录');
+      expect(result.output).toContain('子项数量: 3');
+    });
+
+    it('正确显示符号链接信息', async () => {
+      vi.mocked(fs.stat).mockResolvedValue({
+        ...mockStats,
+        isSymbolicLink: () => true,
+        isFile: () => false,
+      } as any);
+      vi.mocked(fs.readlink).mockResolvedValue('/real/path');
+
+      const result = await getFileInfoTool.execute({ path: 'link' });
+
+      expect(result.success).toBe(true);
+      expect(result.output).toContain('类型: 符号链接');
+      expect(result.output).toContain('链接目标: /real/path');
+    });
+
+    it('正确格式化文件大小', async () => {
+      // 测试不同大小
+      const sizes = [
+        { size: 500, expected: 'B' },
+        { size: 1024, expected: 'KB' },
+        { size: 1024 * 1024, expected: 'MB' },
+        { size: 1024 * 1024 * 1024, expected: 'GB' },
+      ];
+
+      for (const { size, expected } of sizes) {
+        vi.mocked(fs.stat).mockResolvedValue({
+          ...mockStats,
+          size,
+        } as any);
+
+        const result = await getFileInfoTool.execute({ path: 'test.txt' });
+
+        expect(result.output).toContain(expected);
+      }
+    });
+
+    it('权限被拒绝时返回错误', async () => {
+      vi.mocked(getPermissionManager).mockReturnValue({
+        checkFilePermission: vi.fn().mockResolvedValue({
+          allowed: false,
+          action: 'deny',
+          reason: '不允许获取信息',
+        }),
+      } as any);
+
+      const result = await getFileInfoTool.execute({ path: '/protected/file' });
+
+      expect(result.success).toBe(false);
+      expect(result.error).toContain('权限被拒绝');
+    });
+
+    it('需要确认时返回提示', async () => {
+      vi.mocked(getPermissionManager).mockReturnValue({
+        checkFilePermission: vi.fn().mockResolvedValue({
+          allowed: false,
+          action: 'ask',
+          needsConfirmation: true,
+        }),
+      } as any);
+
+      const result = await getFileInfoTool.execute({ path: 'file.txt' });
+
+      expect(result.success).toBe(false);
+      expect(result.error).toContain('需要用户确认');
+    });
+
+    it('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'));
+
+      const result = await getFileInfoTool.execute({ path: 'nonexistent.txt' });
+
+      expect(result.success).toBe(false);
+      expect(result.error).toContain('ENOENT');
+    });
+
+    it('传递正确参数给权限检查', async () => {
+      const mockCheck = vi.fn().mockResolvedValue({ allowed: true });
+      vi.mocked(getPermissionManager).mockReturnValue({
+        checkFilePermission: mockCheck,
+      } as any);
+
+      await getFileInfoTool.execute({ path: 'test.txt' });
+
+      expect(mockCheck).toHaveBeenCalledWith(
+        expect.objectContaining({
+          operation: 'info',
+        })
+      );
+    });
+  });
+});