MEMORY-DREAM-CLEANUP-RESULTS - offline cleanup for finished context

Companion to RECALL-RESULTS.md and CDB-RESULTS.md. Those lanes made a finished session durable and debuggable as a core image. This lane adds the “human dream” pass: while the session is asleep, the kernel re-checks and tidies its memory image without replaying the transcript or asking a model to summarize it.

The claim

A finished session can be auto-cleaned as a page-table-over-CAS image: re-screen resident pages against today’s gate, strand pages whose external witness was later refuted, repair sealed descriptors from metadata only, surface duplicate page aliases, and prune unreferenced swap bytes. The cleaned image still loads through recall.Load, so later page-ins keep the same witness gate and fresh content re-screen.

This leans into FAK-specific features:

• Context MMU: cleanup is a content-admission pass, not a text summarizer.
• Content-addressed pages: duplicate tool results remain distinct page-table frames but share one CAS blob.
• Witness revocation: a page admitted under a refuted source is pre-sealed out of the resident recall set.
• Durable recall: the pass operates on the sleeping core image and writes a new image, leaving the original available for audit.

What shipped

• recall.Dream(ctx, dir, DreamOptions) loads a persisted core image, verifies it, runs the cleanup ledger, and optionally writes a cleaned output image.
• fak dream exposes the pass:

fak dream --dir cdb-image --out-dir dream-image --out dream-report.json
fak dream --dry-run --dir cdb-image

If --dir does not exist, the command seeds a deterministic demo image with a duplicate benign page, one page admitted under a witness that is then revoked, and one already-sealed injection page.

Witnesses

• TestDreamTightenedReScreenSealsFormerlyResidentPage: an old weak image that treated obfuscated injection as benign is cleaned into a sealed page; the safe descriptor does not carry the obfuscated bytes, and page-in refuses with ErrSealed.
• TestDreamSealsRevokedWitnessOutOfTheResidentSet: a refuted witness removes a formerly resident page from recall candidates before any query can fault it in.
• TestDreamPrunesUnreferencedCASAndPreservesBenignBytes: orphan CAS bytes are pruned, duplicate aliases are surfaced, and benign pages still resolve byte-identical.
• TestDreamDryRunDoesNotWriteOutput: dry-run mode reports without writing a new image.

Honest residue

This is deterministic memory hygiene, not generated consolidation. It does not write model summaries, merge semantic memories, or improve the detector itself. Its value is that the cleaned output is a smaller and safer core image under the same mechanical trust gate. A future higher-level “dream” tier can add extractive decision summaries, but those summaries must themselves be admitted as pages and re-screened like any other result.