- Add CheckResult and PreflightResults structs for check outcomes
- Implement runTestCheck() to execute go test -short ./...
- Wire up --check flag to actually run tests instead of placeholder
- Add ✓/✗ output formatting with command and truncated output
- Support --json flag for programmatic consumption
- Exit with non-zero code when tests fail
- Add tests for new preflight functionality
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
