chore(contracts): CHAOS-5777 Pin the cardinality claim's anchor-bound subject shape

[chrisgeo]

Summary

• The dev-health-acr cardinality claim's subject is now the counted population, not always the organization: an anchor-bound count names the anchor itself (kind + canonical id); every other count still names the organization.
• No schema/wire change on either side -- ClaimedFact.subject is already the general SubjectRef shape with no restriction tied to kind == "cardinality".
• This is a test-only sync: corrects the consumer pin's stale doc comment and adds a fixture that exercises the anchor-subject shape alongside the existing organization-subject one, in src/lib/acr/validate.test.ts.

Test plan

• pnpm install (real install)
• pnpm prettier --check (the touched file)
• pnpm lint (the touched file)
• pnpm exec vitest run src/lib/acr/validate.test.ts -- 112/112 passed
• pnpm build (next build) -- succeeded

[linear-code]

CHAOS-5777