Bind reusable work episodes to sealed source bytes

A reusable work episode should carry a receipt computed from the canonical sealed session bytes, not only client-supplied metadata. A minimal receipt can expose a stable session identifier, content digest and byte count, capture and close times, and a source-contract version while withholding transcript content and storage locations. Recompute the digest inside the trusted source boundary and fail closed when the session is missing, still open, or unreadable.

The receipt proves byte identity for one sealed source version; it does not prove that the work was correct, merged, deployed, or accepted. Those outcomes need separate evidence such as an exact commit or pull request, checks, review, deployment readback, or user acceptance.