verify

Pre-commit validation for React contributions with parallel type checking and testing. Run all verification steps. Arguments: Run these first in sequence: Then run these with subagents in parallel: If all pass, show success summary. On failure, stop immediately and report the issue with suggested fixes. - Runs formatting and linting sequentially, stopping on first failure to catch issues early - Executes type checking and dual test suites (source and www) in parallel using subagents for efficiency - Accepts optional test pattern argument to filter which tests run - Provides detailed failure reporting with suggested fixes when any step fails - $ARGUMENTS: Test pattern for the test step - Run yarn prettier - format code (stop if fails) - Run yarn linc - lint changed files (stop if fails) - Use /flow to type check (stop if fails) - Use /test to test changes in source (stop if fails) - Use /test www to test changes in www (stop if fails)