docs: clarify generated release notes behavior

Author: gemxx

.github/release-guideline.md

@@ -62,6 +62,10 @@ Options:
 
 GitHub Release notes are generated by CI. Stable releases compare against the latest previous stable tag (`vX.Y.Z`). Prereleases compare against the nearest previous version tag, including prerelease tags when available.
 
+### Automatic Release Notes Caveat
+
+`What's Changed` is generated by the release workflow through GitHub's `generateReleaseNotes` API, not by parsing commit logs locally. It mainly lists merged pull requests in the selected compare range. Direct commits may only appear in `Full Changelog`; manually add them to the release body if they need to be called out.
+
 ## CI Workflow
 
 Workflow file: [.github/workflows/publish.yml](.github/workflows/publish.yml)

.github/release-guideline.zh-CN.md

@@ -62,6 +62,10 @@ git push origin --tags
 
 GitHub Release notes 由 CI 自动生成。正式版本比较当前版本之前最新的正式版 tag（`vX.Y.Z`）。非正式版本比较最临近的上一个版本 tag，有可用的非正式版本 tag 时也会参与比较。
 
+### 自动 Release Notes 注意事项
+
+`What's Changed` 由发布工作流调用 GitHub 的 `generateReleaseNotes` API 生成，不是本地解析 commit log。它主要展示所选 compare 范围内的 merged PR。direct commit 可能只出现在 `Full Changelog` 中，如需对外说明，需要手动补充到 release body。
+
 ## CI 工作流说明
 
 执行文件：[.github/workflows/publish.yml](.github/workflows/publish.yml)