The diff does exactly what its title and body claim: it deletes `runId: session_01AiXD4y5Y91KC7iM3uBhWmu` / `promptVersion: operator-by-hand-v1` from six deep-memory entries dated 2026-09-09 to 2026-09-11 and two geopolymer entries dated 2026-09-11, and nothing else in those entries changes. Two of the stripped entries state in their own text that 'No run id and no prompt version exist for it because no protocol ran', so the stamps they carried actively misattributed how the work was checked; removing them corrects a §3.8/§3.14 provenance defect rather than creating one. The change is recorded rather than silent: one appended entry per file names what was removed, why (review note #302), the actor, date, and the stamps of the session under which the correction itself was made — the convention of #300 that applies from 2026-09-16 forward. Line counts match the stat (12 lines in deep-memory, 4 in geopolymer) and the per-file 'four entries of 2026-09-16' plus 'two entries of 2026-09-16' reconciles with the body's six. No AGENTS.md edit, no citation identifiers added (verification found none), no confidence material, and no check in §3.15 is loosened — the effect is to make the record reconstructable instead of contradictory. Append-only concerns are satisfied because the retraction of a false stamp is itself logged in the append-only changelog with actor and reason.

The change removes retrospective `runId` and `promptVersion` fields from eight entries whose dates predate the stated convention, including entries that explicitly say no run or prompt version existed. Leaving those fields would create contradictory provenance, whereas the original actor, date, AI-assistance, and change descriptions remain intact. Each correction is recorded by a new append-only history entry that identifies what was removed, why, and the operator responsible, with stamps appropriate to the 2026-09-16 correction itself. The diff neither edits AGENTS.md nor weakens a mechanical check; it corrects inaccurate historical stamps while preserving an inspectable git history.

The change removes anachronistic and contradictory `runId` and `promptVersion` stamps from pre-convention operator history entries in `deep-memory/history.yaml` and `geopolymer/history.yaml` that had been retroactively stamped by PR #291. It accurately reflects that those historical entries predated the by-hand session stamping convention established in #300. The change adheres to §3.8, §3.14, and §3.15 by maintaining truthful provenance records and appends explicit housekeeping history entries documenting the correction.

The diff solely removes runId and promptVersion fields that PR #291 had retroactively applied to eight pre-2026-09-16 operator history entries (six in deep-memory, two in geopolymer), whose own prose in two cases already states that no such stamps exist; the structured fields therefore contradicted the entries and blocked reconstructability. The six/two 2026-09-16 entries that the stamps actually describe keep them, and a new append-only housekeeping entry is added to each file that records exactly what was removed, why (citing review note #302 and the #300 convention’s forward scope), with honest actor/runId/promptVersion stamps for the present session. No citations, assessments, claims, or AGENTS.md are touched; the change restores exact provenance rather than weakening any check.

The change removes runId/promptVersion stamps that PR #291 misapplied to eight pre-convention history entries — including two whose own text states no run id or prompt version exists for them — which is a provenance misattribution under §3.15, not a weakening of any check. Removing a stamp that contradicts the entry it sits on serves §3.8 and §3.14: provenance must let a reader reconstruct what happened, and a false stamp cannot. The removal is documented the append-only way, by new history entries in each file that say what was removed, why, and under which review note, and those new entries are themselves stamped under the convention they invoke. The line counts in the diff (12 removed in deep-memory, 4 in geopolymer) match the stated scope, no content entries are altered beyond the two stamp lines each, no AGENTS.md edit is present, and no citations are added, so fabrication and constitution concerns do not arise.