feat: preserve Change-Id in amend mode

[mhduiy]

在 amend 模式下新增两个功能：

1. 将原 commit msg 作为参考传递给 AI，一般amend的时候不需要再跟-m来指定额外提示词
2. 保留原提交中的 Change-Id（如果存在）

---

1. Added extract_change_id function to parse Change-Id from existing commit messages
2. Added append_change_id function to add Change-Id to new commit messages when not present
3. Modified build_prompt to accept original commit message parameter for reference in amend mode
4. Updated generate_commit_message to extract original Change-Id in amend mode and preserve it in new commit message
5. Added original commit message to AI prompt for better context in amend mode
6. Added comprehensive unit tests for Change-Id extraction and appending functions

Log: Improved commit message generation in amend mode to preserve Change-Id and reference original message

Influence:

1. Test amend mode with existing Change-Id to ensure it's preserved
2. Test amend mode without Change-Id to ensure no extra Change-Id is added
3. Verify AI generates improved commit messages while referencing original content
4. Test Change-Id extraction with various message formats
5. Verify Change-Id appending logic handles edge cases properly
6. Test commit message generation with and without other metadata tags

feat: 在 amend 模式下保留 Change-Id

1. 添加 extract_change_id 函数从现有提交消息中解析 Change-Id
2. 添加 append_change_id 函数在提交消息不存在 Change-Id 时添加
3. 修改 build_prompt 函数以接受原始提交消息参数，用于 amend 模式下的参考
4. 更新 generate_commit_message 函数在 amend 模式下提取原始 Change-Id 并 保留到新提交消息中
5. 将原始提交消息添加到 AI 提示词中，为 amend 模式提供更好的上下文
6. 添加全面的单元测试，覆盖 Change-Id 提取和添加功能

Log: 改进 amend 模式下的提交消息生成，保留 Change-Id 并参考原始消息

Influence:

1. 测试带有现有 Change-Id 的 amend 模式，确保 Change-Id 被保留
2. 测试没有 Change-Id 的 amend 模式，确保不会添加额外的 Change-Id
3. 验证 AI 在参考原始内容的同时生成改进的提交消息
4. 测试不同消息格式下的 Change-Id 提取功能
5. 验证 Change-Id 添加逻辑正确处理边界情况
6. 测试带有和不带有其他元数据标签的提交消息生成

[Copilot]

Pull request overview

This PR enhances the amend mode functionality to preserve Change-Id metadata from original commits and provides the original commit message as context to the AI for better suggestions.

Changes:

• Added extract_change_id() and append_change_id() helper functions to handle Change-Id metadata
• Modified build_prompt() to accept and incorporate original commit messages in amend mode
• Updated generate_commit_message() to extract and preserve Change-Id, and pass original context to AI
• Added comprehensive unit tests for the new Change-Id handling functions

[Copilot]

Consider adding English documentation for this function in addition to the Chinese comment, consistent with project patterns where functions have bilingual documentation or English documentation for better maintainability.

[Copilot]

Consider adding English documentation for this function in addition to the Chinese comment, consistent with project patterns where functions have bilingual documentation or English documentation for better maintainability.