docs(c-03): qualify the +2.4pp claim, which shipped unqualified on a public repo

[arkash20]

caura-ai/caura is public. Two places assert a 79.8% → 82.2% (+2.4pp) improvement as a fact about include_derived, with no provenance and no conditions:

• docs/atomic-fact-fanout/pm-c03-include-derived-blast-radius.md:141 — "the 79.8% → 82.2% (+2.4pp) result is a ranking gain"
• tests/test_pm_c03_include_derived.py:6 — "worth 79.8% vs 82.2% on that harness", naming the customer run

Both are mine, from #1703 and #1708 yesterday. Filed as oss-0924-m-02.

Why it matters

Those figures come from the PersonaMem store — the subject of pm-0918-c-01 and pm-0918-c-05, a store whose headline 85.4% has not reproduced across two later runs (82.5%, 82.2%) with only 71% retrieval overlap against its own record. If 85.4% is untrustworthy because of store state, +2.4pp inherits exactly that doubt. We were publicly claiming an improvement measured on ground we are simultaneously arguing internally that we cannot stand on.

Three qualifications, none of which was stated

It is a floor, not an estimate	Measured client-side, before the server-side exclusion that refills top_k existed. ~24 rows deleted from 85 and not backfilled — a thinner context than a store that never had them.
Recall-boost hysteresis	TrackRecalls bumps recall_count on every returned row, children included, and it feeds the score. Query-time filtering cannot undo a counter children already accrued.
Wrong run to chain	A within-run delta on caura-bulk-2k-top50-sess2, not the record run. Chaining the two predicts 84.6%, which nobody measured.

What replaces it

Not a smaller number — the mechanism, which needs none of this: derived rows compete for top_k slots they were never meant to occupy, and filtering before the trim returns those slots to real memories. That is what the PR actually established, and it stands without a percentage.

Two other mentions were deliberately left alone — both already read "one store, one run, one seed".

Precedent

Same shape as ax-0917-m-28, fixed six days ago: a correctly-sourced lab figure (23ms p50, warm cache, single-tenant) republished without its conditions in eight places until it read as a customer's production latency.

Checks

Docs and one docstring; no behaviour change. 20/20 tests pass, ruff check + format --check clean, legacy-name ratchet reports "No new lines".

🤖 Generated with Claude Code

[github-actions]

Claude Code Review — skipped: PR author 'arkash20' is not a public member of the 'caura-ai' org

[arkash20]

@Eldad-Caura please approve

[github-actions]

Claude Code Review — skipped: PR author 'arkash20' is not a public member of the 'caura-ai' org