[Ambisphaeric]

Refs #178 (slice 1 of N — substrate only).

The durable representation for learned relationships the system lacked — a person works on a repo, a repo belongs to an app, an entity relates to an earlier author. This slice lands the SUBSTRATE only: a typed append-only Claim contract, a deterministic no-model builder, store + relationship queries, and the honest user-correction path. No surface, no model-enriched semantic claims — named OUT below.

What this delivers (per the issue's acceptance criteria)

• Claim contract (shared/contracts/src/records/claim.ts): typed, versioned, append-only Claim — subject → relation → object, grounded only in evidence refs (ClaimEvidenceRef over context-packet/moment/distillate) with minItems:1, so a claim with no evidence is unrepresentable at the schema boundary — every claim traces to source observations. Framed proposal-not-truth: source (derived/user), state (provisional/confirmed/corrected/rejected/superseded), deterministic confidence, ClaimProvenance(builder + evidenceCount = the recorded derivation behind confidence), ClaimCorrection + corrects on sovereign user rows, append-only revision/supersedes, firstObserved/lastObserved = honest valid-time from the evidence.
• The relation-kind decision — CLOSED starter union, justified. ClaimRelation = co-occurs-with · works-on · belongs-to · authored · member-of · relates-to, not an open string: relation is a query axis (and later a UI/semantic axis), so an open string invites un-queryable drift. relates-to is the deliberate generic escape-valve; extending is a reviewed contract change + CLAIM_SCHEMA_VERSION bump + regen (the MomentKind/SummaryLevel precedent). The enum is COMPLETE now even though slice 1's builder emits only co-occurs-with — the sole relation co-occurrence can assert without a model. The semantic kinds are carried by a later judge-enrichment slice (proposals, roadmap: ambient context runtime — canonical ordered execution tracker #189) and by user corrections.
• Deterministic builder (apps/engine/src/index/claims.ts): pure buildClaims derives co-occurrence from entities named together in one ContextPacket's candidates (reusing feat(context): converge separate senses into inspectable ContextPackets #176's converged correlation) or one moment's refs — symmetric endpoints canonically ordered by id, dangling refs never claimed, no evidence ⇒ no claim, confidence a fixed evidence-count map capped <1.0, repeated evidence strengthens only via a NEW revision (never a silent mutation). Content-derived ids ⇒ byte-stable replay (claims-replay.test.ts: same evidence into two fresh stores ⇒ byte-identical). No model this slice.
• Wired at the session-end seam (apps/engine/src/index/produce-claims.ts + api/http.ts): materializeClaims runs AFTER packets materialize, same contained-failure discipline as packets/summaries — never throws, idempotent, batched per session, workspace-isolated.
• Relationship queries (store/workspaces.ts): listClaims by workspace/session/entity(subject∨object)/relation/source/time, with resolveClaimHeads resolving derived-supersession AND user-sovereignty before the filters; relatedEntities = the depth-1 walk (entity → claims → counterparts, always returning the backing claim ids — feat(entity): local candidate search and typeahead person confirmation #181's typeahead substrate); threaded through moveSession. Routes: GET /claims·/claims/related, POST /claims/build·/claims/correct.
• Honest degradation + sovereign corrections: no evidence ⇒ no claims; recordClaimCorrection mints an append-only source:'user' correction that outranks derived without deleting it (the Episode naming: derive and persist a session title from orientation output #211/fix(distill): episode-title sane defaults — judge-lane fallback + zero-model floor + no workspace-id leakage #232 titling-sovereignty pattern) — a REJECT drops the pair from the live view and survives re-derivation.

Out of scope (named — later slices)

Any UI/surface; model-enriched semantic claims (the judge-enrichment pass promoting co-occurrence into works-on/belongs-to/…); #181 entity search/typeahead (this ships the relatedEntities walk it will consume); cross-workspace / app-scoped memory grants (depends on #182 AppRuntime — no dead appId field added).

Determinism / gates

• Determinism proven store-backed (index/claims-replay.test.ts): same evidence built into two fresh stores ⇒ byte-identical claims; rebuild appends nothing; content-derived ids.
• Rebased onto latest origin/main (ab4ece1, contract: 'sessions' block type is used by seeded surfaces but missing from the BlockTypeName union (type widening + no runtime surface validation mask it) #234/fix(contracts): add 'sessions' to BlockTypeName union + restore drift guardrails (#234) #235 folded — conflicts were the append-only CODE_MAP/PHASE4-NOTES tails, resolved keeping both).
• Gates green under Node 22: contracts 114 (+3), fixtures 15, client 606 (one parallel-load flake, green on isolated rerun), engine 1090 (+21). Schemas regenerated zero-drift.
• CODE_MAP (UNION) + PHASE4-NOTES updated in the same change. Not merged.