ADR: dossier JSON-LD provenance extension — design for T-010

Status: proposed (design only — not implemented in this pass; the implementation is blocked on docs/coop/TASKS.md T-001, see below). Date: 2026-07-30.

Measured current state

Current Claim JSON-LD node (templates/partials/jsonld.html):
  {@type: "Claim", name: CLM-##, text, inLanguage, url,
   appearance: [source nodes]}

Current source citation node (templates/macros/jsonld.html, ld_source_node):
  {@type: NewsArticle|WebPage|Article|OpinionNewsArticle,
   url, name, publisher.name, datePublished}
  -- no dateRetrieved, no content hash, no archival reference,
     despite every source's front matter already tracking `retrieved`.

Relationship graph (data/dossiers/<slug>/graph.toml): typed edges
  already exist, but emit NO JSON-LD today -- only Person/Claim/
  WebPage nodes are generated, no relation/edge nodes at all.

Binding constraints (unchanged by this ADR):
  - npm run verify:jsonld fails the build on any truth-rating markup
    (ClaimReview, reviewRating) -- not up for revision here.
  - docs/constitution/OPEN_INTELLIGENCE_COMMONS.md, invariant/§8:
    "Zadne netransparentni ciselne skore pravdy, nikdy... zadny trust
    skore, zadna gamifikace obvineni."

data/coop/TASKS.md T-010 ("Veřejné JSON-LD export routes — /data/*.jsonld, manifest, checksums — dnes JSON-LD jen embedded v HTML") already anticipates a manifest/checksum concept without a concrete design. This ADR gives it one.

Question asked

Site owner asked to extend vomaste.cz's dossier JSON-LD "using the goodies of prismatic-platform" — a much larger sibling platform with a formal provenance/chain-of-custody architecture. Researched prismatic-platform's docs/architecture/adr/ADR-028-provenance-spine-chain-of-custody.md and ADR-035-reference-topology-core.md (read-only; different stack — Elixir/Phoenix — so code doesn't port, only data-model ideas can).

What was researched

• ADR-028 "Provenance Spine": a Source → Request → Artifact → Extraction → Assertion chain. Artifacts are content-addressed (SHA-256 of raw fetched bytes); Assertions are derived claims carrying a numeric confidence (0.0–1.0); multi-source corroboration combines via combined_confidence = 1 - Π(1 - confidence_i); signed manifests ({claim, artifact_hash} triples + overall hash, ED25519) let a whole evidence chain be independently re-verified end to end.
• ADR-035 "Reference Topology": a general bidirectional graph with 16 typed, inverse-paired edge relationships (e.g. an edge type and its defined inverse), cycle policy, temporal (valid_from/valid_to) edges.
• prismatic's actual JSON-LD generator (apps/prismatic_web/lib/prismatic_web/seo/structured_data.ex) is plain SEO schema.org (Article/Person/Organization/FAQ) — not wired to the provenance spine at all. So "prismatic's JSON-LD" isn't itself the useful part; the provenance and graph data models are.

Decision (proposed)

Three ideas adopted, one explicitly rejected, one noted as already present.

Adopt 1 — content-address every cited source. Add a hash (SHA-256 of the archived snapshot if/when this project starts archiving fetched pages, or at minimum of the url + retrieved + outlet tuple as an interim citation fingerprint) to each SRC-##'s front matter, surfaced in ld_source_node. Lets a reader verify a citation still points at exactly the evidence a claim was built on — this is provenance, not adjudication, and doesn't touch the constitution's trust-score ban.

Adopt 2 — a manifest + offline verify script, giving T-010 an actual shape. Concretely: /data/dossiers/<slug>.jsonld (a full @graph export per dossier) + /data/manifest.json listing {route, sha256} for every exported file + a small scripts/dossier/verify-export.mjs that anyone (a fork, a downloader, a journalist double-checking the dataset) can run offline against a downloaded copy to confirm nothing was altered post-export. No signing-keypair infrastructure in v1 (see Revisit threshold) — a plain SHA-256 manifest already delivers this site's own promise: "reprodukuj build a zpochybni výsledek."

Adopt 3 — a small, invertible relationship vocabulary for the existing relation graph. graph.toml already has typed edges, but they emit no JSON-LD today. Extend the export with a minimal custom @context term set, inverse-paired the way ADR-035 pairs its edge types: vomaste:corroborates / vomaste:corroboratedBy, vomaste:supersedes / vomaste:supersededBy. Explicitly excluded from v1: any contradicts/disputes term — even a purely structural "these two sources disagree" edge reads too close to adjudication for a first pass. Revisit only via an explicit AGENTS.md editorial-rules discussion, never bundled into a technical ADR.

Reject — numeric confidence / combined-confidence scoring. prismatic's combined_confidence = 1 - Π(1 - confidence_i) is a reasonable formula for prismatic's own use case, but putting any numeric confidence field on a Claim node directly contradicts this project's own constitution (§8: no opaque numeric truth score, no trust score, no gamified accusation). The existing categorical status enum (CORROBORATED / 1 ZDROJ / SPORNÉ / CITACE / NÁZOR) is this site's deliberate, non-numeric answer to the same underlying "how strong is this claim" question. Replacing or augmenting it with a float would be an editorial-model scope change, not a JSON-LD technical change — and nothing in AGENTS.md's authorization log authorizes that regardless of technical merit.

Already have — the Artifact/Assertion split. vomaste.cz's existing Source (raw, cited, dated) vs. Claim (derived, atomic, statused) split already is this pattern, arrived at independently. Noted here only so a future reader doesn't wonder why it's missing from "adopted."

Why this isn't implemented yet

Every file this design touches — templates/macros/jsonld.html, templates/partials/jsonld.html, source/relation front matter under content/dossiers/**, and any new scripts/dossier/*.mjs — sits inside T-001's active scope-check zone (the entity-dossier physical-decoupling migration, in progress at the time of writing; see docs/coop/TASKS.md). T-010 is board-blocked on T-001 for exactly this reason. This ADR exists so that dependency resolves into a ready, pre-argued design instead of a blank page once T-001 merges — the actual implementation is T-010's job, not this commit's.

Revisit threshold

• Implement content-hash citations + the manifest/verify script as T-010's concrete scope, once T-001 is merged on the coop board.
• Revisit signed (not just hashed) manifests if/when the site needs to prove authorship of an export, not just integrity — e.g. once forks start redistributing dossier exports and provenance-of-the- export-itself becomes a real question, not just provenance-of-the- claims-within-it. Not justified by measured need today (zero forks redistributing exports exist).
• Revisit a contradicts/disputes relationship type only via a dedicated AGENTS.md editorial-rules amendment, never as a follow-up to this technical ADR.