- Move the import pipeline runtime factory into core.imports.pipeline
- Move the metadata runtime factory into core.metadata.enrichment
- Keep the web server wiring thin and drop the shared glue module
- Add contract tests that keep the two runtime bundles separate
- Move the metadata and MusicBrainz-related tests into a dedicated tests/metadata subfolder.
- Keep the rest of the suite flat for now.
- Preserve the existing test filenames so the change stays organizational rather than behavioral.