Every release member now declares publishConfig.access: public, so the scope no
longer mixes levels: the 221 packages/*/* and apps/* manifests join the vendored
framework and the native packages.
check-workspace-constraints drops the per-sequence expectation and holds every
release member to public, which is what stops a member from drifting back.
Access is a property of the package, not of a version: the dsh packages already
published as restricted become world-readable at their next publication.
SessionPersistence.readRaw previously used undefined for two unrelated states: a supported backend could not find the requested session, or the backend had no per-session artifact concept at all. The export endpoint consequently reported an existing SQLite-backed session as HTTP 404, which falsely diagnosed storage capability as session absence.
Make raw-artifact support an explicit backend capability. Unsupported backends now fail their inherited readRaw path loudly and the host answers 501 before reading, while undefined retains the single meaning of an absent artifact on a supporting backend. First-party backends, test providers, generated API catalogs, bilingual persistence docs, and export error contracts now state that distinction; focused tests cover both the 501 and the inherited rejection.