- 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>