Extended the legacy Pi, TypeBox, package-import alias, and extension graph regexes to recognise the bare \"import \\"specifier\\";\" shape so side-effect-only loads such as \"import \\"#src/register\\";\" walk into the source graph and get their legacy @(scope)/pi-* imports rewritten. Added a regression that loads a plugin with a side-effect alias import whose target contains a legacy scope import.\n\nFixes #1889