feat(goofish): auto-generate cna if cookie is missing to fix search API error

[Bugegoo]

📋 Pull Request 信息 | PR Information

🔗 关联 Issue | Related Issue

• Closes [Question]: 商品检索没结果 #12
• Related to #(issue_number)
• 没有关联 Issue | No related issue

📝 变更类型 | Type of Change

请选择适用的变更类型 | Please check the type of change your PR introduces:

• 🐛 Bug 修复 | Bug fix (non-breaking change which fixes an issue)
• ✨ 新功能 | New feature (non-breaking change which adds functionality)
• 💥 破坏性变更 | Breaking change (fix or feature that would cause existing functionality to not work as expected)
• 📚 文档更新 | Documentation update
• 🎨 代码风格 | Code style update (formatting, renaming)
• ♻️ 重构 | Refactoring (no functional changes, no api changes)
• ⚡ 性能优化 | Performance improvement
• ✅ 测试相关 | Test related changes
• 🔧 构建/工具 | Build/tooling changes
• 🚀 其他 | Other (please describe)

📖 变更描述 | Description

Previously, initializing a new Goofish instance without a cookie would result in missing the required 'cna' parameter.
This would cause the search API to return the error:
RGV587_ERROR::SM::哎哟喂,被挤爆啦,请稍后重试

Now, if no cookie is provided, a default 'cna' parameter is automatically generated
during initialization, ensuring the search API works correctly.

什么变更？| What changed?

为什么变更？| Why was this change needed?

如何变更？| How was this implemented?

🧪 测试 | Testing

测试步骤 | Test Steps

• 已在本地环境测试 | Tested locally
• 已运行现有测试套件 | Ran existing test suite
• 添加了新的测试用例 | Added new tests
• 已在多个环境测试 | Tested in multiple environments

测试环境 | Test Environment

• Node.js 版本 | Node.js Version:
• 操作系统 | OS:
• 其他相关环境 | Other relevant environment:

测试结果 | Test Results

# 请粘贴测试输出或截图
# Please paste test output or screenshots

📸 截图/视频 | Screenshots/Videos

📚 文档 | Documentation

• 我已更新了相关文档 | I have updated the relevant documentation
• 我已更新了 API 文档 | I have updated the API documentation
• 我已更新了 README | I have updated the README
• 我已添加了代码注释 | I have added code comments
• 不需要文档更新 | No documentation update needed

⚠️ 破坏性变更 | Breaking Changes

• 此 PR 包含破坏性变更 | This PR includes breaking changes

破坏性变更详情 | Breaking Change Details

影响的 API | Affected APIs:

迁移指南 | Migration Guide:

向后兼容性 | Backward Compatibility:

📋 检查清单 | Checklist

代码质量 | Code Quality

• 我的代码遵循了项目的编码规范 | My code follows the project's style guidelines
• 我已经进行了自我代码审查 | I have performed a self-review of my own code
• 我已经注释了代码中难以理解的部分 | I have commented my code, particularly in hard-to-understand areas
• 我的变更没有产生新的警告 | My changes generate no new warnings
• 代码通过了 linting 检查 | Code passes linting checks

测试覆盖 | Test Coverage

• 我已添加了测试来覆盖我的变更 | I have added tests that prove my fix is effective or that my feature works
• 新的和现有的单元测试都通过 | New and existing unit tests pass locally with my changes
• 任何依赖的变更都已合并和发布 | Any dependent changes have been merged and published

文档和示例 | Documentation and Examples

• 我已更新了 TypeScript 类型定义 | I have updated TypeScript type definitions
• 我已添加或更新了使用示例 | I have added or updated usage examples
• 我已更新了 [CHANGELOG.md](http://changelog.md/) | I have updated [CHANGELOG.md](http://changelog.md/)
• 我已检查了文档中的链接 | I have checked that documentation links work

安全和性能 | Security and Performance

• 我已考虑了这些变更的安全影响 | I have considered the security implications of these changes
• 我已测试了性能影响 | I have tested for performance implications
• 我没有暴露敏感信息 | I have not exposed sensitive information
• 我遵循了安全编码最佳实践 | I have followed secure coding best practices

🔍 Review 注意事项 | Review Notes

重点关注区域 | Areas of Focus

已知问题 | Known Issues

📦 发布影响 | Release Impact

• 这是一个补丁版本 | This is a patch release (bug fixes)
• 这是一个次要版本 | This is a minor release (new features)
• 这是一个主要版本 | This is a major release (breaking changes)
• 这不需要发布 | This doesn't require a release

🏷️ 额外标签 | Additional Labels

建议的标签 | Suggested labels: bug, enhancement, documentation, dependencies, security, performance, breaking-change

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✅ 准备就绪确认 | Ready for Review Checklist

• 我已阅读并理解了[贡献指南](https://11273.github.io/goofish-client/guide/contributing)
• 我确认这个 PR 已经准备好进行审查
• 我理解 maintainers 可能会要求修改
• 我同意这个贡献将在项目许可证下发布

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PR 提交者签名 | Submitter Signature: @Bugegoo