First increment toward 90% core-package coverage. Adds Docker-free unit
tests taking these packages to full or near-full coverage:
- provider/npm, provider/alpine, provider/puppet: 100%
- provider/pypi: index generation via a fake FileStore, upload validation,
name parsing, classification, rewrite
- config: defaults, overrides, DSN, invalid port
- auth: basic header with/without credentials
Infra-backed packages (database, storage, cache, proxy engine, api
handlers, server) still need the testcontainers batch to reach 90%.
