fix-missing-verisim-feed: retired generic "hexad" format value in the feed template #621

Problem

scripts/fix-missing-verisim-feed.sh generates a feed manifest for repos that lack one, and the template hard-codes:

[feed-config]
emit-scan-results = true
emit-build-metrics = true
emit-dependency-graph = true
format = "hexad"
destination = "verisim-data/feeds/"

hexad is a count-specific word (six) used generically here — it never meant a six-element record — and it is easily mistaken for a six-element contract. Upstream's named eight-modality contract is Octad; the number-agnostic term for a selected/configured group of modalities is modality profile.

Because this script is the source of that value, fixing it in one consumer repo is not enough: the value is re-stamped for the next repo that gains a feed. An org-wide code search for the template's emit-scan-results key returns 224 hits across hyperpolymath repos (2026-10-25).

What the consumers actually do with it

Nothing schema-level, as far as we can tell:

• hyperpolymath/stateful-artefacts src/bridges/verisimdb-feed.sh writes records tagged "feed-format": "provisional-v0" — it does not emit hexad — and carries the note "Provisional local record only; no upstream modality-profile mapping or network sink."
• In hyperpolymath/reposystem the key has no in-repo reader at all; it is annotated as a legacy alias from this template rather than changed, precisely because a local edit would diverge.

So this looks like a vestigial label, not a discriminator any emitter consumes — but confirm across the estate before changing it.

Proposed change

1. Replace the generic format = "hexad" in the template with format = "modality-profile" (or drop the key and record the equivalence in a comment), whichever matches the agreed estate wording.
2. Keep any transitional alias accepted by consumers; do not promise variable-arity support.
3. Optionally emit a note that the record shape is implementation-specific and is not the upstream Octad contract.
4. Decide whether existing generated manifests are migrated (a bulk sweep) or left as-is with a documented alias.

Naming variance to resolve at the same time

The script targets verisim.a2ml / verisim-data, while reposystem (and others) carry verisimdb.a2ml / verisimdb-data. If the canonical name is verisimdb, the generator and the existing files disagree — worth settling in the same pass.

Context / prior art

• Terminology decision: Define modality-profile terminology and cardinality semantics verisimdb#299 (modality profile for a selection; Octad reserved for the current upstream eight-modality API).
• Consumer-side cleanup: Clarify VeriSimDB modality-profile terminology in integrations reposystem#299 → docs(verisimdb): clarify modality-profile terminology, label five-store client legacy/custom (#299) reposystem#326 (merged) and docs(verisimdb): evidence for the retained hexad format value — retire it in the estate template (#299 follow-up) reposystem#328 (evidence note: docs/VERISIMDB-MODALITY-PROFILE.adoc).
• Emitter that already avoids the word: hyperpolymath/stateful-artefacts src/bridges/verisimdb-feed.sh.

Raised from the reposystem #299 follow-up; no transport or schema change should ride along with the rename.