Add ability to replace a FeedSourceProvider at runtime and propagate
the new source to all active (and pending) user sessions, invalidating
their feed caches.
Co-authored-by: Ona <no-reply@ona.com>
Rename all references across the codebase: package names,
imports, source IDs, directory names, docs, and configs.
Co-authored-by: Ona <no-reply@ona.com>