chore: remove CLAUDE.local.md from tracking and update gitignore

[sanity]

Summary

• Remove CLAUDE.local.md from git tracking (should be local only)
• Add *.local.md pattern to .gitignore to prevent future commits
• CLAUDE.md was already removed, only local instructions remain

Changes

• Removed CLAUDE.local.md from git tracking using git rm --cached
• Added *.local.md to .gitignore to ensure local instruction files stay local
• No build artifacts or other untracked files are included in this PR

This ensures that local development instructions (CLAUDE.local.md) remain on developer machines only and are not tracked in the repository.