fix(catalog): entry detail endpoint only reads range42.yaml and 404s for real entries

[pparage]

The catalog entry detail endpoint (app/routes/v1/catalog/entries.py, GET /v1/catalog/entries/{source}/{path}) only parses range42.yaml, which does not exist for any real catalog entry. Every container (meta.json) and every role (meta/main.yml) returns 404, so the UI detail view (README, topology preview) is always empty. The detail handler should branch on manifest type the same way the _discover walker does.