clay-borg/workplans/CB-WP-0019-the-am4-family.md

id	kind	title	status
CB-WP-0019	meta	The AM-4 family's last two defects, and the self-quoting rule	todo

Purpose

structural tier  M   (changes how the loop constrains its own operation:
                      a budget's scope and target, and a reporting rule)
chaos            d8 = 5  → no override
declared tier    M

Declaration 2 of chaos window 2, and the first roll at d8.

Meta budget is 0% over the trailing three, all product. ADR-0006 D2 exempts instrument repair anyway, and this is the repair four evidence files have listed as owed.

Two numbers that have been owed for five passes

Both were measured before this declaration, so the work is scoped against facts rather than an intention to find them.

AM-4b's scope, owed since CB-EV-0012 §3:

	crates	lines
AM-4b as instrumented (games-ground, --edges normal)	29	317,021
the whole workspace, dev edges included	57	725,258
uncounted	28	408,237

The dev-toolchain budget is blind to more source than its own target of 350,000. criterion, clap, ciborium, quick-js and now cb-game-runtime's dev graph are all invisible to it.

AM-4b's proc-macro share, owed since ADR-0008 D2: 109,585 lines, 15.1% of the real graph.

That 15.1% is worth stating plainly, because it vindicates a decision made for the right reason. ADR-0008 D2 refused to correct AM-4b using AM-4a's measured 36.2%, saying "correcting a second instrument on the strength of the first one's ratio is the error this change exists to fix." The shares are 36.2% and 15.1%. Borrowing would have been wrong by a factor of more than two.

Task: give AM-4b a scope, and a target that matches it

id: CB-WP-0019-T01
status: todo
priority: high

Decide what AM-4b is for, then instrument that.

The two honest candidates, and the choice needs an argument rather than a default:

• Widen it to the whole workspace with dev edges — everything a contributor's cargo test acquires. Then the target must move with the instrument, exactly as ADR-0008 D3 moved AM-4a's, and the target moves to fit the measurement, not the measurement to fit the target.
• Narrow the claim to what it actually measures and rename it, if "one package's non-dev graph" is the thing worth bounding.

Whichever wins, do not repeat ADR-0008 D3's generosity by reflex. That decision gave back a small rounding-up because a target with 1.5% of room fails on a patch release; a target set 130% above the current reading would not be a budget at all.

Controls:

• the mutation must still go red — AM-4b's row is currently enforced and must stay so;
• a test that the configuration measures what its name says: if it claims dev edges, a dev-only dependency must move the number. quick-js is the case to use, because it is dev-only and it is what exposed this.

Task: the proc-macro share, decided not just measured

id: CB-WP-0019-T02
status: todo
priority: high

15.1% is measured. What is owed is the decision: does the dev budget exclude proc-macro crates as the shipped one does?

The shipped case was easy — a proc-macro never reaches a shipped binary, so counting it in "what a game ships" was simply wrong. The dev case is not the same question. A proc-macro is acquired, is compiled, is unaudited third-party source on a contributor's machine, and the acquisition rule (ADR-0007 D3) counts what the build causes to be fetched.

So the arguments point opposite ways and the answer is not inherited. Decide it, and say which of the two rules governs when they disagree.

Whatever is decided, ADR-0008 D2's note that AM-4b's share is unmeasured must stop being true in the source.

Task: write the self-quoting rule down

id: CB-WP-0019-T03
status: todo
priority: high

Six passes, six under-reports, both halves of the defect diagnosed, and the rule still lives only in evidence files:

pass	reported mid-flight	settled	under by
CB-WP-0009	$6.73	$11.31	40%
CB-WP-0011	$4.23	$7.02	40%
CB-WP-0012	$8.82	$14.52	39%
CB-WP-0013	$5.78	$8.26	30%
CB-WP-0015	$15.14	$22.70	33%
CB-WP-0017	$5.19	$9.48	45%

Six for six, always low, never by less than 30%. That is not noise; it is a systematic bias with two identified causes (CB-EV-0013 §5, CB-EV-0015 §6):

1. a pass's window runs to the next pass's first commit, so the previous pass is not final until the one after it starts;
2. a figure read earlier in a session is an in-flight figure regardless of whose name is on it — quoting from memory defeats the rule even when the boundary is right.

Put it in specs/InnerLoop.md as a rule with both halves, and make loop-lint check what it can. A rule that lives only in prose has been re-derived three times already.

The honest question to answer while writing it: is the right rule "quote two passes back", or "re-run the instrument at quote time", or both? T03 of CB-WP-0018 used the second and it worked. Say which is load bearing.

Task: evidence

id: CB-WP-0019-T04
status: todo
priority: high

evidence/CB-EV-0017-*.md.

• The AM-4 family, closed or not. Four defects found across five passes, none by looking for them. State whether any remain and whether the family is now trustworthy — and if a fifth is plausible, say where.
• What five passes of being "owed" cost. These two numbers were carried as open items in four consecutive evidence files. Either the carrying was cheap and correct, or it was a way of not doing the work; say which, with the cost.
• Quote CB-WP-0018's cost by re-running the instrument. Under the rule T03 writes down.
• Chaos: declaration 2 of 12 in window 2, first roll at d8.