File-Upload and Media-Handling Posture: A Proposed Axis for What an AI Builder's Upload Path Actually Permits (August 2026)
A proposed BuilderProof benchmark axis measuring whether the file-upload path an AI app builder emits is owner-scoped, content-verified, bounded and durable, or whether it only works because the developer testing it is the only account in the app. Six weighted signals, four posture levels, a reproducible protocol.