skills: tool-version provenance + the cross-repo seam (plugin 0.21.0)

[avrabe]

Closes #164. Closes #165. Both tested by execution before any skill was edited.

#164 — measured worse than reported

The report claimed differing warning counts between rivet versions. On one unchanged tree (varve @ a640673, 158 artifacts) the verdict flips:

rivet	result	exit
0.19.0	FAIL — 60 errors, 62 warnings	1
0.28.0	FAIL — 60 errors, 72 warnings	1
0.32.0	PASS — 72 warnings	0

The output names the cause: unknown artifact type 'verification' — an old binary rejecting a type the newer schema ships. So the rule had to be stronger than "record the version":

• an old binary's FAIL can be a schema-capability artifact, not a finding — chasing it burns a cycle on a tool gap;
• an old binary's PASS can miss rules it never implemented — the silent direction, and the one that ships as evidence.

That is traceability-audit step 0's question one layer down, so the new step cross-links it rather than restating it.

Pin claim verified, not just repeated: relay's verification-gate.yml and release.yml both pin rivet v0.19.0; the current layer ships 0.32.0. The required gate really is the laxest check in the system.

#165 — the block already works; the declaration is what's missing

rivet verify refuses to promote without evidence — measured, exit 1. So the mechanism to hold a requirement is there. What rivet has no field for is who owns the unrun criterion.

external-anchor is not that field: it models the inbound supplier boundary (source-of-truth, received-as-reqif, received-as-polarion-export) — requirements handed to us. The outbound case, a criterion owed by a downstream consumer, has no typed home. So the skills prescribe the convention that works today (name the owner in the requirement, hold at implemented, tag it, block the release), and the capability request goes upstream.

Scope calls

• Skills field report: requirements can be owned outside the repo — the cross-project seam is missing in both directions #165 proposal 3 folded into proposal 1. oracle-gate-a-change step 3 already mandates kill-criteria; what the report actually adds is the externally-owned case plus one prompt — name what would still be false if every check you can run passes. One line in step 3, not a new methodology section.
• The varve coverage boundary is stated once, in the roster — it carries the tools that check our work, not the upstream ones that build it (wasm-tools, cargo-component, wkg; varve#52) — rather than repeated in each skill that mentions varve which.

Verification

• 16/16 skills parse under strict YAML; names match directories
• every changed version line is frontmatter; plugin.json diff is exactly one line
• plugin 0.20.0 → 0.21.0

🤖 Generated with Claude Code

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