clay-borg/workplans/CB-WP-0006-instrument-the-table.md

id	title	status
CB-WP-0006	Instrument the acceptance table, then implement what it exposes	proposed

Purpose

CB-WP-0005 T02 measured M-D1-MUT for the first time:

  M-D1-MUT: 4/14 rows enforced
    PARTIAL       2      (AM-7, AM-8 — some clauses live, some inert)
    unmutatable   8      (no property to invert)

4 of 14, against a predicted 10 of 14. The prediction was wrong by 2.5×, and wrong about what as well as how much: CB-RES-0004 diagnosed three absent kernel rules, and the measurement found that more than half the acceptance table has no instrument behind it at all.

CB-WP-0005 Phase C was deferred before starting on that basis (T02's stop condition, maintainer decision 2026-07-31). It was scoped to five rules — K9, K10, K11, K14, K18 — which does not address the eight.

This workplan is scoped to what was measured rather than what was predicted. Phase A instruments the unmeasured rows; Phase B implements the kernel work inherited from CB-WP-0005 T04–T06. That order is the whole point: the previous pass built a fix before its instrument existed, and the instrument then contradicted the fix's premise.

Per InnerLoop §Step 4, no target moves in the commit that measures it.

Phase A — instrument the rows that measure nothing

Task: AM-6 — assert the throughput target

id: CB-WP-0006-T01
status: todo
priority: high

The sharpest single finding of CB-WP-0005. Nothing in the workspace compares any number to 100,000 events/s — the project's headline throughput claim, reported as met, 16.5×. The Criterion bench emits throughput; the only asserts in synthetic.rs are the stress-gate shape and the events-per-round pin.

Deliver a standing assertion — a test, not a bench — that measures applied events/s on the synthetic workload and fails below the AM-6 target.

The trap, stated up front: a timing assertion in CI is flaky by nature, and the usual response is to loosen it until it never fires, which would reproduce exactly the defect being fixed. So the threshold is pinned well below the measured 1.65M/s (AM-6 asks for 100k), the assertion states its own headroom in the failure message, and a loosening requires an ADR. A gate tuned until it cannot fire is a gate that counts names.

Verified by: make mutation-check --row AM-6 goes from unmutatable to red.

Task: AM-2, AM-3 — instrument the size metrics

id: CB-WP-0006-T02
status: todo
priority: medium

AM-2 (≤40 spec lines per rule) and AM-3 (≤50 LOC for the synthetic workload) are both unmutatable for the same reason: make loc prints line counts and nothing divides, compares, or gates.

AM-2 is the anti-gaming pair for AM-1 — 100% rule coverage means nothing if the rules are trivially small — so an uninstrumented AM-2 leaves AM-1 gameable, which is the specific risk MetricsAndScenarios §1 names when it introduces M-D1-SPL.

AM-3 depends on K18 (benches driven from scenario files); if K18 resolves toward amending the spec rather than implementing it, AM-3 must be restated or withdrawn with an argument rather than left unmeasured.

Task: AM-5, AM-9 — measure or withdraw, but stop leaving them blank

id: CB-WP-0006-T03
status: todo
priority: medium

AM-5 (clean build ≤60 s) is recorded not gated — and not recorded either. AM-9 (peak RSS ≤64 MB) is declared "very unlikely to bind", which CB-EV-0001 itself calls out as an unmeasured judgment call.

Both are cheap to measure: one time around a clean build, one /usr/bin/time -v around the 100k-event run. Or withdraw them with an argument, which is a legitimate outcome and possibly the right one for AM-5 on a machine-dependent number. What is not legitimate is a third pass leaving them blank while the scoreboard reports elsewhere.

Task: AM-4c — target it or drop it

id: CB-WP-0006-T04
status: todo
priority: low

reported, not targeted, so there is no property to invert and it counts against M-D1-MUT by ADR-0005 §1.

Two honest options, and the task must pick one with an argument: give it a threshold (making it enforceable), or remove it from the acceptance table and keep it as a reported diagnostic. A row in an acceptance table that cannot fail is decoration, and this pass has learned to say so.

Note the incentive: ADR-0005 already predicts own-source growth from the kernel work in Phase B, so AM-4c will move against us. Setting its threshold after seeing that movement would be the retarget InnerLoop §Step 4 forbids — so it is set here, before Phase B, or not at all.

Phase B — the kernel work inherited from CB-WP-0005

These three carry their full analysis in CB-WP-0005 Phase C, where they were written and then deferred unstarted. They are summarized here; read that file for the detail, the four replay controls, and the D2 correction on what the bundle writer actually requires.

Task: K9 and K11 — durable log, LogStore port, real conformance suite

id: CB-WP-0006-T05
status: todo
priority: high

Inherited from CB-WP-0005 T04. K9's acceptance property (snapshot at N + events N+1..M ≡ genesis fold) is mutation-proven unasserted; K11 has no durable format at all. The LogStore port with a shared fn conformance<S: LogStore>(…), retro-fitted to KernelRng, is what finally earns AM-11 — currently downgraded to unmet because the pair exists and the suite does not.

Verified by: make mutation-check --row AM-11 goes from unmutatable to red.

Task: K10 — the replay bundle and --replay

id: CB-WP-0006-T06
status: todo
priority: high

Inherited from CB-WP-0005 T05. INTENT design decision 8 of 10, unimplemented. All four controls from ADR-0005 §6 are required verbatim, including the two the adversarial reviewer supplied: truncate-by-one-byte rejection, and a mutated-seed control so the round-trip is capable of failing.

Fixing this is also what lets AM-7's withdrawn hash-identical clause be re-earned, since a real replay is what the clause was always about.

Task: K14 and K18 — implement, or amend the spec and say why

id: CB-WP-0006-T07
status: todo
priority: medium

Inherited from CB-WP-0005 T06. CommitWindow has zero non-test users; the bench never touches ScenarioFile. Either wire them up or amend the rules with a recorded argument. Deleting a rule to make a gate green is forbidden; deleting one with an argument is legitimate and probably right for K18.

Phase C — measure, and answer the question this pass inherited

Task: control loop — M-D1-MUT before and after

id: CB-WP-0006-T08
status: todo
priority: high

Commit evidence/CB-EV-0004. The baseline is 4 of 14, committed and reproducible via make mutation-check.

Three tests, all reported:

1. Did the enforced count rise, per row? Against the per-task predictions above, unmet reported as unmet.
2. Did any row regress from red to SURVIVED? The four currently enforced rows are the ones with something to lose.
3. Were the new mutations strong? CB-WP-0005 T02 wrote two no-op mutations on its first attempt, either of which would have published a false accusation against working code. Every mutation added by this pass must be shown to fail for the stated reason — record how that was checked.

Task: retrospective — is a weak mutation the new grep?

id: CB-WP-0006-T09
status: todo
priority: medium

The question CB-WP-0005 T08 raised and this pass is positioned to answer.

CB-WP-0004 concluded that tooling recovers capacity only where it removes the manual path. M-D1-MUT does not remove a manual path — writing a weak mutation is exactly as easy as writing a strong one, and the harness cannot tell the difference. CB-WP-0005 produced two no-op mutations on its first attempt, so the failure mode is demonstrated, not hypothetical.

And it fails in the more dangerous direction: a weak mutation does not merely miss a defect, it indicts working code. A false SURVIVED sends the next pass to fix something that is not broken.

So: is M-D1-MUT a real instrument, or a name-counter with extra steps? If the latter, say so and propose what would actually bind — the candidate being that the mutation must be written by someone other than the author of the assertion, which is the adversarial-review principle applied one level down.