scientific(relation): require owner-issued provenance before Observed activation #675

Finding

Review after #673/#674 exposed an authority gap one boundary earlier than numerical admission. relation_graph::RelationEvidenceStatus correctly distinguishes Observed (direct source/authoritative-system evidence) from Inferred (model/reasoner/heuristic proposal), and #673 now excludes Inferred transitions from TRSL-TM numerical estimation. However, the public RelationEdge::new(...) constructor still accepts RelationEvidenceStatus::Observed directly from any caller.

As a result, a caller that owns no source-evidence authority can manufacture an otherwise-valid edge with Observed status and thereby cross the #673 numerical gate. The enum documents promotion semantics, but the type/API does not yet prove who performed that promotion or which immutable source evidence supports it.

This issue is distinct from #674 (relation interval ↔ modeled EventTime consistency) and #671 (document/source event-time authentication). It is the relation evidence-activation authority boundary.

Required owner path

Do not solve this by adding a boolean, string provenance field, locally hashing source text, or trusting LLM output. The observed constructor must eventually consume a versioned owner-issued Evidence/Temporal Semantics receipt or ACL contract that binds at minimum:

• source evidence identity/version;
• relation kind and endpoint identities;
• event-valid source/target intervals used by the relation;
• availability/cutoff evidence appropriate to the observation;
• promotion/derivation authority sufficient to distinguish documentary observation from model inference.

Inferred relation construction must remain available for model/reasoner proposals without granting numerical authority. Promotion must be an explicit validated owner transition, not caller mutation of an enum.

Required RED once owner contract is available

• direct downstream construction of an Observed relation without owner evidence is impossible or fails closed;
• an Inferred proposal cannot become Observed by changing a status value or deserializing an unbound payload;
• an owner-issued observed receipt reconstructs the relation and preserves its validated temporal intervals;
• A-source/B-relation or A-receipt/B-endpoint substitution fails;
• scientific(relation): exclude unpromoted inferred transitions from numerical estimation #673 estimator behavior remains: only properly activated Observed transitions can influence objective/uncertainty/lineage;
• no LLM output, semantic label, or heuristic can issue the authoritative activation.

Dependency / boundary

#527/#658 currently own the mutable Evidence/source receipt work and are not released consumer authority. Define the final cross-context ACL only after that owner contract settles; do not copy SourceSnapshotReceiptV1 source or invent a parallel receipt in topic_measurement.

Refs #527 #638 #639 #658 #671 #673 #674.