gates: doc-refs and orphan-artefacts red on main -- #510 debt plus agents.json after gHashTag/t27#8054 #908

Goal

doc-refs and orphan-artefacts are red on main (09662bb) and on every PR built on it, for reasons none of those PRs touch. Make both green on main by fixing the references, not by changing either checker.

Where we are

• orphan-artefacts and most of doc-refs: the debt left by gft_mul: the product wire is 32 bits and GF-T32 needs 52 #510, measured and fixed in fix(gates): green doc-refs and orphan-artefacts on main after #510 #872 (commit 7cf4429, gate data and one inventory document, no checker code). fix(gates): green doc-refs and orphan-artefacts on main after #510 #872 is open since 2026-10-04.
• doc-refs on fix(gates): green doc-refs and orphan-artefacts on main after #510 #872's own head is still red (job 114088519511) for one new reason: AGENTS.md and CLAUDE.md write the format name agents.json in backticks. The checker reads a backticked *.json as a path, and until t27b vacuous: delete 22 empty generated spec stubs (Closes #8052) t27#8054 deleted .trinity/seals/agents.json (2026-10-09) that name matched an unrelated file in t27 by basename, so it sat in tools/doc_refs_crossrepo.txt as a cross-repo reference. It never referred to that file: the sentence lists file formats outside tools expect (llms.txt, ai.txt, A2A agent cards, ...).
• Blocked by this: docs(conformance): section 4 of FORMATS_ON_BOARD.md points to the two TNF board runs #904 (Closes FORMATS_ON_BOARD.md section 4 still says TNF was never on this board #903), fix(trinet): a coordinator restart no longer pays the same (node, nonce) again #907 (Closes trinet: a coordinator restart pays the same (node, nonce) again -- durable journal, nonce mark, write before credit #906).

Boundary

• No change to tools/check_doc_refs.py or tools/check_orphan_artefacts.py.
• No new doc_refs_baseline.txt entry for agents.json.
• fix(gates): green doc-refs and orphan-artefacts on main after #510 #872's commit is carried unchanged, with its author.

Success Criteria

1. doc-refs and orphan-artefacts green on the PR head and on main after merge.
2. Negative control: putting the backticks back makes doc-refs fail with exactly AGENTS.md: names \agents.json`, which does not exist`.

Dmitrii Fedorov (@dmitrii-f-t27)