feat(t214): persist candidate observation identities

backend-api/internal/repository/sqlite/candidate_decision_repository.go

@@ -7,6 +7,7 @@ import (
 	"encoding/hex"
 	"encoding/json"
 	"errors"
+	"strconv"
 
 	"cmroubao/backend-api/internal/domain"
 	"cmroubao/backend-api/internal/usecase"
@@ -93,6 +94,25 @@ func storeCandidateDecisionDataset(
 		if err != nil {
 			return repositoryFailure(err)
 		}
+		_, err = tx.ExecContext(
+			ctx,
+			`INSERT INTO candidate_observation_identities (
+				candidate_key, execution_id, candidate_ordinal,
+				card_signature, detail_signature, detail_evidence_sha256,
+				specification_evidence_sha256, identity_version, created_at
+			) VALUES (?, ?, ?, ?, ?, ?, ?, 1, ?)`,
+			candidateObservationKey(write.ExecutionID, candidate),
+			write.ExecutionID,
+			candidate.Ordinal,
+			candidate.CardSignature,
+			candidate.DetailSignature,
+			candidate.DetailEvidenceSHA256,
+			candidate.SpecificationEvidenceSHA256,
+			formatTimestamp(write.Now),
+		)
+		if err != nil {
+			return repositoryFailure(err)
+		}
 	}
 	if batch.ProvenanceJSON != nil {
 		var provenance usecase.ExecutionProvenance
@@ -567,12 +587,21 @@ func getCandidateDecisionDataset(
 	}
 	rows, err := queryer.QueryContext(
 		ctx,
-		`SELECT task_id, execution_id, ordinal, title, sku_text, price_text,
-			product_url, image_url, evidence_asset_ids_json,
-			collection_status, observed_at
-		FROM candidate_observations
-		WHERE task_id = ? AND execution_id = ?
-		ORDER BY ordinal ASC`,
+		`SELECT observation.task_id, observation.execution_id,
+			observation.ordinal, observation.title, observation.sku_text,
+			observation.price_text, observation.product_url,
+			observation.image_url, observation.evidence_asset_ids_json,
+			observation.collection_status, observation.observed_at,
+			identity.candidate_key, identity.card_signature,
+			identity.detail_signature, identity.detail_evidence_sha256,
+			identity.specification_evidence_sha256,
+			identity.identity_version, identity.created_at
+		FROM candidate_observations AS observation
+		LEFT JOIN candidate_observation_identities AS identity
+			ON identity.execution_id = observation.execution_id
+			AND identity.candidate_ordinal = observation.ordinal
+		WHERE observation.task_id = ? AND observation.execution_id = ?
+		ORDER BY observation.ordinal ASC`,
 		taskID,
 		executionID,
 	)
@@ -582,6 +611,9 @@ func getCandidateDecisionDataset(
 	for rows.Next() {
 		var observation domain.CandidateObservation
 		var evidenceJSON, observedAt string
+		var candidateKey, cardSignature, detailSignature sql.NullString
+		var detailHash, specificationHash, identityAt sql.NullString
+		var identityVersion sql.NullInt64
 		if err := rows.Scan(
 			&observation.TaskID,
 			&observation.ExecutionID,
@@ -594,6 +626,13 @@ func getCandidateDecisionDataset(
 			&evidenceJSON,
 			&observation.CollectionStatus,
 			&observedAt,
+			&candidateKey,
+			&cardSignature,
+			&detailSignature,
+			&detailHash,
+			&specificationHash,
+			&identityVersion,
+			&identityAt,
 		); err != nil {
 			_ = rows.Close()
 			return nil, repositoryFailure(err)
@@ -610,6 +649,24 @@ func getCandidateDecisionDataset(
 			_ = rows.Close()
 			return nil, repositoryFailure(err)
 		}
+		if candidateKey.Valid {
+			identityCreatedAt, parseErr := parseTimestamp(identityAt.String)
+			if parseErr != nil {
+				_ = rows.Close()
+				return nil, repositoryFailure(parseErr)
+			}
+			observation.Identity = &domain.CandidateObservationIdentity{
+				CandidateKey:                candidateKey.String,
+				ExecutionID:                 observation.ExecutionID,
+				CandidateOrdinal:            observation.Ordinal,
+				CardSignature:               cardSignature.String,
+				DetailSignature:             detailSignature.String,
+				DetailEvidenceSHA256:        detailHash.String,
+				SpecificationEvidenceSHA256: specificationHash.String,
+				IdentityVersion:             int(identityVersion.Int64),
+				CreatedAt:                   identityCreatedAt,
+			}
+		}
 		dataset.Observations = append(dataset.Observations, observation)
 	}
 	if err := rows.Err(); err != nil {
@@ -823,6 +880,23 @@ func hashCandidateResult(candidates string, recommendation *string) string {
 	return hex.EncodeToString(digest.Sum(nil))
 }
 
+func candidateObservationKey(
+	executionID string,
+	candidate usecase.ExecutionCandidate,
+) string {
+	digest := sha256.New()
+	_, _ = digest.Write([]byte("cmroubao-candidate-v1"))
+	_, _ = digest.Write([]byte{0})
+	_, _ = digest.Write([]byte(executionID))
+	_, _ = digest.Write([]byte{0})
+	_, _ = digest.Write([]byte(strconv.Itoa(candidate.Ordinal)))
+	_, _ = digest.Write([]byte{0})
+	_, _ = digest.Write([]byte(candidate.DetailSignature))
+	_, _ = digest.Write([]byte{0})
+	_, _ = digest.Write([]byte(candidate.SpecificationEvidenceSHA256))
+	return hex.EncodeToString(digest.Sum(nil))
+}
+
 func nullableSQLString(value sql.NullString) any {
 	if !value.Valid {
 		return nil