InstallCommand enhancements:
- --list-components, --check, --no-migrate flags
- --with-shield / --without-shield (default ON when relevant component selected)
- --with-pint / --without-pint (default ON when binary exists)
- runtimeEnvSeedContent blanks sensitive credential keys
- credential leak warn after seed file generation
- laravel/boost availability check via Artisan::has()
- printPostInstallSummary using EnvReader redacted output

Idempotent: shield:safe-regenerate, pint, env summary all safe to re-run.