Download declared external payloads without blocking local edits, then cache exact bytes and SHA-256 transactionally. Reject changed identities, stale references, and damaged cached data while preserving the edit queue. Include media in read-only recovery exports.

Migrate existing live caches to schema 5 and retain original schema-4 archive compatibility. Verify actual legacy cache migration, concurrent download/edit behavior, abrupt process exit, live Samba downloads followed by offline reopen, full workspace regressions, and iOS device/simulator linking.

Assisted-by: gpt-6-astra