Summary

Investigate and implement .gitattributes rules to enforce LF line endings for agent files (.agent.md, .prompt.md) to prevent cross-platform YAML parsing issues.

Background

During the ADR-040 amendment review (PR #895), the independent-thinker agent identified that CRLF line endings may be a contributing factor to Windows YAML parsing errors, not just inline array syntax.

Evidence

• GitHub Copilot CLI Issue feat(validator): add investigation-only session QA skip validation #694: Agents fail to load if frontmatter has CRLF line endings documents the exact "Unexpected scalar at node end" error with CRLF files
• Current state: .gitattributes does not enforce line endings for *.agent.md or *.prompt.md files
• Risk: Windows Git defaults to CRLF, which can cause YAML frontmatter parsing failures

Related

• ADR-040 amendment debate log: .agents/critique/ADR-040-amendment-2026-01-13-debate-log.md
• Original issue: YAML parsing error on *.agent.md files #893

Proposed Changes

Add to .gitattributes:

# Agent files: enforce LF for cross-platform YAML compatibility
*.agent.md text eol=lf
*.prompt.md text eol=lf
*.shared.md text eol=lf

Acceptance Criteria

• Research best practices for cross-platform line ending management
• Add .gitattributes rules for agent-related markdown files
• Verify existing files have correct line endings (run git ls-files --eol)
• Document rationale in .gitattributes comments
• Test on Windows to confirm YAML parsing works with LF-normalized files

Priority

P2 - Preventive maintenance. The immediate issue (inline arrays) is fixed in PR #895, but this addresses a potential secondary cause.

Source: ADR-040 multi-agent debate review (independent-thinker dissent)