clay-borg/workplans/CB-WP-0042-h2-scoped-problem-stress.md

id	kind	title	status	state_hub_workstream_id
CB-WP-0042	product	H2 — scoped problem stress	done	8f11d55b-3452-49f3-9857-d0bf06752f68

Purpose

structural tier  M   (touches a canonical interface: edition loading
                      becomes variant-parameterised, and the kernel gains
                      per-Problem state)
chaos            d8 = 4  → no override
declared tier    M

Declaration 2 of chaos window 4.

Why, and it is a direct answer to ours

We reported that H1-A behaves as a solve-rate tax: a flat +1 to every seat while any Problem is unclaimed, so the pressure scales with the number of Problems while the intended effect does not.

ground-game responded with H2 — scoped problem stress. Unclaimed Problems now tick only the seats in their scope:

scope	who takes the +1
global	all seats
personal	the Problem's owner
bond	the owner's Bond network — owner plus every seat reachable over Bond edges only, never Rivalry; degree 0 falls back to personal

Assigned by hidden priority: 0 (Surface) global, 1 personal, 2 personal, 3 bond, 4 personal — which is a seat-band dial without a difficulty card, since 2p never has the bond card in play.

It does not stack with H1. replaces_experiments: [h1-problem-stress], base is ground-darvo-r0, and there is no ATTACK self-soothe.

Why this is bigger than H1 was

H1 was two arithmetic deltas on existing state. H2 needs three things we do not have:

1. Variant-scoped edition data. H2 overrides Problems.csv with a new stress_scope column. edition.rs include_str!s r0's copy at compile time — the data is currently a constant, not a parameter.
2. Per-Problem ownership, assigned at setup. That is new state, so it reaches the state hash and every recording.
3. Bond-network reachability — a graph traversal over Bond edges only, with a degree-0 fallback.

Task: variant-scoped edition data

id: CB-WP-0042-T01
status: done
priority: high
state_hub_task_id: "37f9bc34-05d1-4a12-9a98-6c61ab3ec23f"

Controls:

• the baseline's data is bit-for-bit what it was, and its state hashes do not move — the control that protected CB-WP-0038 and the one that invalidates every prior measurement if it fails;
• the H2 package is vendored with digests like every other borrowed file, and edition-check covers it — sibling discovery walks the disk now, so an undigested file fails (CB-REV-0003 #8);
• stress_scope's assignment is read from the file, not hardcoded. The delta states the priority→scope mapping; it is the edition's to state and ours to read, and F25 exists because we hardcoded numbers the edition already carried.

Done 2026-08-08. Package vendored with digests; edition-check walks it. StressScope and stress_scopes() read the column.

H2's Problems.csv is r0's with one column added and nothing else changed — same rows, values, suits, visibilities and priorities. That is checked, not assumed: the delta claims deal_and_thresholds unchanged, and a silent difference would make every H2-vs-baseline comparison a comparison of two boards as well as two rule sets.

Task: ownership at setup

id: CB-WP-0042-T02
status: done
priority: high
state_hub_task_id: "65b9b2b8-8160-488f-8cd4-b7f734d03b22"

H2-OWN: ascending hidden priority among in-play non-global Problems, starting at Lead, stepping clockwise. Global Problems have no owner.

Controls:

• deterministic, and asserted so — the delta says "deterministic for sims" and a seeded-but-unstated order would be untestable;
• the baseline carries no owners and its hash does not move. New state that is None under baseline must serialise as it did before, or every recorded scenario breaks;
• exactly one owner per eligible Problem, checked at every seat count, because the assignment walks two sequences at once and off-by-one is the obvious failure.

Done 2026-08-08. owner and scope on ProblemState, both Option, both skip_serializing_if = "Option::is_none" — so a baseline state serialises without them and every recorded scenario's hash is untouched. Asserted directly, on the JSON.

with_variant() replaces the bare field write. state.variant = v would leave owners unassigned — a silently wrong game rather than a failing one — so the builder applies the variant's setup and every driver path goes through it.

Task: scoped pressure

id: CB-WP-0042-T03
status: done
priority: high
state_hub_task_id: "8426e79c-579e-4aba-a695-381020016206"

H2-A, at Round End, before the clamp and the DARVO arm check — the same ordering H1-A needed, and the same trap.

Controls:

• each scope fails on its own, by mutation: global hitting only the owner, personal hitting everyone, bond stopping at the owner;
• stacking: true is tested — two open bond Problems must tick the network twice, and a careless implementation applies it once;
• Rivalry edges are not traversed. The delta says Bond only, and a traversal that follows any relation is the single most likely defect;
• degree 0 falls back to personal, which is the branch a test forgets;
• ordering asserted as in CB-WP-0038: pressure before the arm check.

Done 2026-08-08. All four named defects mutation-proven:

mutation	caught by
traverse Rivalry edges too	h2_bond_scope_does_not_traverse_rivalry
stacking applied once	h2_pressure_stacks_per_problem
degree-0 owner ticks everyone	h2_a_bond_problem_with_no_bonds_is_personal
personal hits everyone	h2_pressure_reaches_only_the_scope

The degree-0 mutation missed first, and that is worth recording: the fallback lives inside bond_network, and the first mutation broke the None-owner arm instead — a different branch. It stayed green until the mutation was aimed at the path the test actually exercises. A mutation that misses is not evidence the test works.

Task: SOLVE is not restricted by scope

id: CB-WP-0042-T04
status: done
priority: medium
state_hub_task_id: "6606cb3b-733d-486c-9e46-37a2a2b0c2c9"

H2-SOLVE: any seat with a matching suit may claim; the owner need not be the solver, and altruistic clearing is intended.

Control: our engine has no owner concept today, so this is already true — which makes it a regression test, not a feature. T02 adds ownership, and the risk is that ownership silently becomes a permission. The test must fail if it does.

Done 2026-08-08, and it does: filtering SOLVE to the owner in legal_commands turns it red.

Task: measure, and report what fails

id: CB-WP-0042-T05
status: done
priority: high
state_hub_task_id: "0bcd97da-60b8-46b2-ae86-7a94f6af8dd5"

Same instrument as H1, same panel, both variants in one run.

Controls:

• greedy and reactive both, because H1's whole verdict turned on which policy was asked (CB-EV-0031);
• report against ground-game's own criteria for H2, from their design note — read it, do not reuse H1's §3.2 from memory;
• the bond-scope hypothesis is the interesting one and must be measured directly: their claim is that a shared tick makes a Bond network jointly motivated to solve that card. Whether a policy that does not model other seats can express that at all is an open question, and the honest answer may be "our panel cannot test this hypothesis";
• make panels runs it, or the figures come from an ungated binary again (CB-REV-0002 #7).

Done 2026-08-08. CB-EV-0032. H2 largely succeeds where H1 failed.

#	their criterion	verdict
1	greedy SHARED 3–4p above H1's 0	met — 120 and 175 against H1's 0 and 0
2	variance above baseline and H1-greedy	met at 2p/4p/6p, missed at 3p (1.50 vs 1.57)
3	DARVO for a policy that still sometimes wins	met — H1's clearest failure, now 13/13/57 wins with arms
4	bond SOLVE rate above personal	not met, and untestable here
5	control: all scopes global → collapse	met decisively — 120→0 and 175→0

Criterion 5 is the best evidence in the pass. Forcing every scope to global and changing nothing else reproduces H1's collapse exactly, which says the scoping is what saves it rather than any other difference between the packages.

Criterion 2's mechanism is visible in the numbers: H1-greedy's spread is 0.00 at 3p+. A flat tax on every seat creates no variance at all, which is the clearest statement of why scoping was the right correction.

Criterion 4 came out backwards, and the prediction held. The workplan said our panel might not be able to test it, because no policy here models another seat or knows what a scope is. Bond claim rates are lower than personal at 3p and 4p — driven by suit availability, not by incentive. Reported as untested with an incidental figure pointing the wrong way, not as a refutation.

Not in this workplan

• No stacking with H1. The package forbids it explicitly.
• No felt-play. H2's central claim is about motivation — a bonded pair caring about each other's card — and 200-game aggregates measure dynamics, not that (Taxonomy.md §4).