fix: audit platform contracts and relation identities

backend/api/internal/logic/platform/task4_resources.go

@@ -102,7 +102,7 @@ func listResource(ctx *gin.Context, model any) {
 		infra.Response.Error(ctx, err)
 		return
 	}
-	infra.Response.Success(ctx, gin.H{"total": total, "list": resourceResponse(list.Elem().Interface())})
+	infra.Response.Success(ctx, gin.H{"total": total, "list": publicResourceResponse(list.Elem().Interface())})
 }
 
 func getResource(ctx *gin.Context, model any) {
@@ -111,7 +111,7 @@ func getResource(ctx *gin.Context, model any) {
 		respondRecordError(ctx, err)
 		return
 	}
-	infra.Response.Success(ctx, resourceResponse(data.Interface()))
+	infra.Response.Success(ctx, publicResourceResponse(data.Interface()))
 }
 
 func createResource(ctx *gin.Context, model any, allowedFields []string, relations []ResourceRelation) {
@@ -230,6 +230,113 @@ func resourceResponse(value any) any {
 	return stripInternalIDs(decoded)
 }
 
+// publicResourceResponse additionally resolves persisted relation keys into
+// their public identities. It is used by list/detail endpoints so an edit form
+// can round-trip the relation without ever receiving a surrogate database ID.
+func publicResourceResponse(value any) any {
+	encoded, err := json.Marshal(value)
+	if err != nil {
+		return value
+	}
+	var decoded any
+	if err := json.Unmarshal(encoded, &decoded); err != nil {
+		return value
+	}
+	return projectRelationIdentities(decoded)
+}
+
+var relationIdentityModels = map[string]any{
+	"gas_basic_id":            &models.GasBasic{},
+	"gas_station_id":          &models.GasBasic{},
+	"delivery_basic_id":       &models.DeliveryBasic{},
+	"delivery_point_id":       &models.DeliveryBasic{},
+	"user_account_id":         &models.UserAccount{},
+	"staff_account_id":        &models.StaffAccount{},
+	"smart_cylinder_valve_id": &models.DevSmartCylinderValve{},
+	"ec_category_id":          &models.EcCategory{},
+	"ec_product_id":           &models.EcProduct{},
+	"ec_order_id":             &models.EcOrder{},
+	"delivery_task_id":        &models.DeliveryTask{},
+	"delivery_track_id":       &models.DeliveryTrack{},
+	"platform_role_id":        &models.PlatformRole{},
+	"platform_menu_id":        &models.PlatformMenu{},
+	"report_id":               &models.Report{},
+	"wallet_id":               &models.Wallet{},
+}
+
+var relationIdentityKeys = map[string]string{
+	"gas_station_id":    "gas_basic_identity",
+	"delivery_point_id": "delivery_basic_identity",
+}
+
+func projectRelationIdentities(value any) any {
+	switch data := value.(type) {
+	case map[string]any:
+		for key, item := range data {
+			if key == "id" {
+				delete(data, key)
+				continue
+			}
+			if strings.HasSuffix(key, "_id") {
+				identityKey := strings.TrimSuffix(key, "_id") + "_identity"
+				if alias := relationIdentityKeys[key]; alias != "" {
+					identityKey = alias
+				}
+				model := relationIdentityModels[key]
+				if key == "subject_id" {
+					model = settlementSubjectModel(data["subject_type"])
+					identityKey = "subject_identity"
+				}
+				if model != nil {
+					data[identityKey] = relationIdentity(item, model)
+				}
+				delete(data, key)
+				continue
+			}
+			data[key] = projectRelationIdentities(item)
+		}
+	case []any:
+		for index := range data {
+			data[index] = projectRelationIdentities(data[index])
+		}
+	}
+	return value
+}
+
+func relationIdentity(value any, model any) string {
+	var id uint64
+	switch raw := value.(type) {
+	case float64:
+		id = uint64(raw)
+	case uint64:
+		id = raw
+	case int:
+		id = uint64(raw)
+	}
+	if id == 0 {
+		return ""
+	}
+	var related struct{ Identity string }
+	if err := impl.DBService.Model(model).Select("identity").Where("id = ?", id).First(&related).Error; err != nil {
+		return ""
+	}
+	return related.Identity
+}
+
+func settlementSubjectModel(value any) any {
+	subjectType, _ := value.(string)
+	switch subjectType {
+	case "gas", "gas_basic":
+		return &models.GasBasic{}
+	case "delivery", "delivery_basic":
+		return &models.DeliveryBasic{}
+	case "staff", "staff_account":
+		return &models.StaffAccount{}
+	default:
+		return nil
+	}
+}
+
 func stripInternalIDs(value any) any {
 	switch data := value.(type) {
 	case map[string]any:
@@ -311,7 +418,7 @@ func GetEcOrder(ctx *gin.Context) {
 		infra.Response.Error(ctx, err)
 		return
 	}
-	infra.Response.Success(ctx, resourceResponse(gin.H{"order": order, "items": items}))
+	infra.Response.Success(ctx, publicResourceResponse(gin.H{"order": order, "items": items}))
 }
 
 // GetDeliveryTrack returns time-ordered points. Precise coordinates are only
@@ -337,7 +444,7 @@ func GetDeliveryTrack(ctx *gin.Context) {
 			points[index].Latitude = ""
 		}
 	}
-	infra.Response.Success(ctx, resourceResponse(gin.H{"track": track, "points": points}))
+	infra.Response.Success(ctx, publicResourceResponse(gin.H{"track": track, "points": points}))
 }
 
 type ecCategoryView struct {