Memory lineage preservation across sessions

[drk-ram]

Proposal for #501: Preserve the original source facts, derivation namespace, and effective taint across memory writes and later reads. Require provenance on every strict retrieval result, bind persistent entries to stable identifiers, and handle unresolved lineage as untrusted or deny.

The schema and normative prose changes are scoped to this issue, with regression coverage and strict documentation validation. Feedback on downstream compatibility is welcome.