* fix: remove dangling skills: from agent frontmatter and strip in Gemini converter (closes #1023, closes #953, closes #930) Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> * fix: invert skills frontmatter test to assert absence (fixes CI) The PR deliberately removed skills: from agent frontmatter (breaks Gemini CLI), but the test still asserted its presence. Inverted the assertion to ensure skills: stays removed. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com> --------- Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>