Release notes: OpenClaw 2026.5.18

[github-actions]

Generate release notes markdown for OpenClaw 2026.5.18 following our release notes guidelines.

Upstream GitHub Release:

• https://github.com/openclaw/openclaw/releases/tag/v2026.5.18

Guidelines:

• release-notes/GUIDELINES.md (in this repo)

Tasks:

• Pull changes/changelog from upstream OpenClaw release/tag v2026.5.18
• Draft a release-notes/ markdown file in zh-TW
• Follow guidelines (分類：功能更新/安全性提升/錯誤修復；每項標註⭐；含用途/解決問題/影響)
• Include ## ⚠️ 升級前必讀 section with Breaking Changes table and 新功能亮點 (required if release has breaking changes; omit if none)
• Include link(s) to the upstream GitHub Release

Acceptance:

• New md file committed in claw-info under release-notes/
• 升級前必讀 section present if release has breaking changes
• Issue closed via PR