merge-main

Sync the current feature branch with main by committing local work, fetching and merging origin/main, and resolving conflicts. Use when user says 'merge main', 'update from main', 'sync with main', 'pull main into branch', 'branch is behind main', 'rebase on main', or 'update my branch'. Do NOT use for creating PRs (use /create-pr), reviewing code (use /review-diff), or running tests (use /test-scope).