Records, not bytes
The platform’s value lives one layer above byte storage — the graph of people, places and things a record refers to. Apps keep their bytes; the platform keeps the meaning.
The first cut owned the bytes and was abandoned; the framework later retrodicted why. An abstraction pays only when the complexity it saves exceeds its own cost plus the expressiveness it takes away, and abstracting bytes takes away everything an app knows about its own storage.
Curator, the knowledge-graph service in Nexus, abstracts where the tradeoff is cheap: it ingests records — photos, documents, messages — resolves the people and places they reference into shared entities, and serves them back filtered by row-level security. It never stores or serves a byte of the originals.