registry.py is a SQLite-backed store (its class is already RegistryStore),
so it belongs with the other orchestrator-owned stores rather than at the
package root. Moved orchestrator/registry.py -> orchestrator/store/
registry_store.py, joining queue_store / secret_store / config_store.
Repointed the in-package importers (.registry -> .store.registry_store)
and the tests, bumped the moved file's relative-import depths, renamed
the test file to match, and listed it in the store package docstring.
Full unit suite green (2243).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
