Greptile fixes:
- Removed non-standard YAML frontmatter fields (observe, feedback, rollback) from all 4 skills — only name, description, origin, version per CONTRIBUTING.md
- Added null guard to checkInteractions implementation (was missing despite test)
- CI: replaced 2>/dev/null with 2>&1 (was silencing safety-critical errors)
- CI: quoted $RESULT variable (was breaking jq on JSON with spaces)
- CI: added division-by-zero guard when test suite is empty
- CI: added note that Jest is reference implementation, thresholds are framework-agnostic
9b24bedf85