Teach the profile installation fallback to use normal symlinks under Node and real ESM proxy packages under pkg. Each proxy records the source package version, mirrors its explicit runtime subpath exports, and re-exports the virtual /snapshot URLs, so built-in Loader rows and external plugin peers resolve one shared Cordis/module instance from an on-disk profile.
Keep proxy healing idempotent, reject foreign real directories, cover root and subpath imports in packaged mode, and expand AggregateError startup diagnostics so concurrent Loader failures retain their individual import causes. This is the reusable packaged-profile mechanism; Python-specific artifact wiring remains in the next commit.
809a4c5bad