clay-borg/workplans/CB-WP-0021-import-the-edition.md

id	kind	title	status
CB-WP-0021	product	Import the edition: the game plays its own data	ready

Purpose

structural tier  M   (adds or refuses an external dependency, and changes
                      how a game is set up — a canonical interface)
chaos            d8 = 7  → no override
declared tier    M

Declaration 4 of chaos window 2.

The engine has been playing a stand-in

games/ground/src/lib.rs builds Problems with value: priority and suits cycled by index. editions/ground-darvo-r0/Problems.csv has carried the real thing since 2026-07-31, and GROUND-WP-0002 T01 ruled it authoritative on 2026-08-03:

	problems/scenario	values	total	suits
Problems.csv	5	2, 2, 2, 3, 3	12	required_solution per problem
the stand-in	3	1, 2, 3	6	cycled by index

GR-E01's thresholds are 2p → 5, 3–4p → 7, 5–6p → 9. Ordinary against 12, unreachable against 6 — which is why the maintainer's last game ended 0 scores and winners nobody, and why clay-borg has been carrying GR-E01 unreachable below 5 seats as a rules gap for ground-game to rule on. It was never a rules gap.

The constraint, measured before declaring

AM-4a has 3,798 lines of headroom. A CSV crate costs, marginally against the shipped graph:

crate	lines
csv	14,291
csv-core	3,360
ryu	3,962
marginal total	21,613

5.7× the available headroom. itoa, memchr, serde and serde_core are already present and cost nothing; the parser itself is what does not fit.

So the shipped runtime cannot gain a CSV parser, and that is settled by measurement rather than by preference. What remains is which of the alternatives to take, and that is the ADR.

Task: decide how the data reaches the game

id: CB-WP-0021-T01
status: todo
priority: high

Write decisions/ADR-0011-*.md (tier M: survey and decision in one).

Three questions, and the third is the one that bites.

(a) Where does the data live? ground-game is a separate repository. Depending on a sibling checkout makes the build depend on a path that may not exist; vendoring a copy makes clay-borg carry content it does not own. Whichever is chosen must say how a copy is known to be current, because a silently stale copy is worse than no copy.

(b) How is it parsed, given a CSV parser does not fit? Candidates, and each needs its marginal cost stated rather than assumed:

• hand-rolled reader in games/ground — small, but it is a parser we then own, and problem_text contains commas;
• bake it: a dev-time step converts the CSV into a generated Rust module or compact literal, so the shipped runtime parses nothing. Then the generated artifact must be proven to match its source, which is the DFD class this repo already has machinery for;
• load nothing at runtime and treat the data as scenario input.

(c) What does this do to determinism? Problem values and required suits become part of GroundState, which is hashed (K7). Every recorded state hash changes. Before writing code, establish what actually pins a hash today — make sim runs 25 scenarios, replay-test re-executes bundles, and AM-7's probe asserts per-segment hashes. Say which of those break, and whether any of them are supposed to be stable across a content change.

This is the reason the ADR exists. A content import that quietly invalidates every recorded hash, in a project whose central invariant is replay determinism, is not a data-loading change.

Task: import it, and let the thresholds mean something

id: CB-WP-0021-T02
status: todo
priority: high

Replace the stand-in. setup must build Problems from the edition data: point_value, required_solution, visibility (Surface → face up, Hidden → face down) and hidden_priority.

Controls:

• The stand-in must become unreachable. A test that the fixture constants no longer appear — a value: priority that survives beside real data is a fallback nobody will notice until the numbers look odd again.
• A scenario must be able to reach GR-E01's threshold at 2 players, which is the specific thing that was impossible. Assert the arithmetic, not just that a game runs.
• The 5-problem shape must survive: the stand-in dealt 3, and code that assumed 3 will not announce itself.

Task: retire the rules gap that was never one

id: CB-WP-0021-T03
status: todo
priority: medium

gr-e01-threshold-unreachable-2p is tagged provisional: true with provisional_owner: ground-game, and its description says group success "is unreachable at 2, 3 and 4 players". If T02 lands, that scenario is asserting a property of the stand-in, not of the game.

Retire or rewrite it, and say which of the six provisional items this resolves, so GROUND-WP-0002 T03 shrinks rather than being left to rediscover it. Message ground-game with the outcome — the last such message sat unread for four days because nothing pointed at it.

Do not quietly delete a failing-in-fact scenario. CB-EV-0005: a score improved by deleting the question is not an improvement.

Task: evidence

id: CB-WP-0021-T04
status: todo
priority: high

evidence/CB-EV-0019-*.md.

• What the import cost, against the 3,798 lines that were available.
• What broke, especially hashes, and whether the blast radius was predicted in T01 or discovered in T02. If it was discovered, say so — that is the ADR having missed something.
• Whether the endings now mean anything: play one and report the score against the threshold.
• Quote CB-WP-0020's cost by re-running the instrument.
• Chaos: 4 of 12 in window 2.