ci: generate release notes with git-cliff

[eetoc]

Summary

• Generate Release Notes with git-cliff for v* tags.
• Keep runtime and historical client release lines out via tag_pattern.
• Replace the fixed Release body with the generated release-notes.md.

Validation

• Local git-cliff 2.13.1 offline generation passed.
• Workflow YAML parsing passed.
• git diff --check passed.

Notes

• Existing installer assets and idempotent upload behavior remain unchanged.
• The release job has pull-requests: read permission for PR metadata.

[monkeyscan]

PR Title: ci: generate release notes with git-cliff

Commit: 9f342af

本次变更引入了 git-cliff 自动生成 Release Notes 的功能，包含两部分：

1. 新增 cliff.toml 配置文件，定义了 conventional commits 解析规则、标签匹配模式 ^v[0-9].* 以及 GitHub 远程仓库信息。
2. 修改 .github/workflows/images.yml 的 release job：添加 fetch-depth: 0 以获取完整 Git 历史，集成 orhun/git-cliff-action@v4 生成 release-notes.md，并将 gh release create 的 --notes 参数替换为 --notes-file release-notes.md。

整体评估：变更简洁合理，使用官方 git-cliff-action，权限控制良好（job 级别 pull-requests: read + contents: write），无明显的正确性、安全或可靠性风险。