fix(billing): 修正模型计费配置继承优先级

apps/api/internal/store/platform_models.go

@@ -23,6 +23,7 @@ type modelCatalogSnapshot struct {
 	DisplayName            string
 	Capabilities           map[string]any
 	BaseBillingConfig      map[string]any
+	PricingRuleSetID       string
 	DefaultRateLimitPolicy map[string]any
 	RuntimePolicySetID     string
 	RuntimePolicyOverride  map[string]any
@@ -121,10 +122,10 @@ func (s *Store) createPlatformModel(ctx context.Context, q platformModelQuerier,
 	if err := validateEnabledVolcesTextModelCapabilities(ctx, q, input, capabilities); err != nil {
 		return PlatformModel{}, err
 	}
+	// billing_config is a legacy, explicitly supplied compatibility field. Do
+	// not materialize base-model pricing into it: copied prices become stale as
+	// soon as the base pricing rule changes and can mask the authoritative rule.
 	billingConfig := input.BillingConfig
-	if len(billingConfig) == 0 {
-		billingConfig = mergeObjects(base.BaseBillingConfig, input.BillingConfigOverride)
-	}
 	explicitRuntimePolicySetID := strings.TrimSpace(input.RuntimePolicySetID)
 	rateLimitPolicy := input.RateLimitPolicy
 	if len(rateLimitPolicy) == 0 && explicitRuntimePolicySetID == "" {
@@ -260,6 +261,8 @@ RETURNING id::text, platform_id::text, COALESCE(base_model_id::text, ''), model_
 	model.ModelType = decodeStringArray(modelTypeBytes)
 	model.BillingConfigOverride = decodeObject(billingOverrideBytes)
 	model.BillingConfig = decodeObject(billingBytes)
+	model.BaseBillingConfig = base.BaseBillingConfig
+	model.BasePricingRuleSetID = base.PricingRuleSetID
 	model.PermissionConfig = decodeObject(permissionBytes)
 	model.RetryPolicy = decodeObject(retryPolicyBytes)
 	model.RateLimitPolicy = decodeObject(rateLimitPolicyBytes)
@@ -368,7 +371,7 @@ func (s *Store) lookupBaseModel(ctx context.Context, q platformModelQuerier, id
 	var modelTypeBytes []byte
 	err := q.QueryRow(ctx, `
 SELECT id::text, provider_key, canonical_model_key, provider_model_name, model_type, display_name,
-       capabilities, base_billing_config, default_rate_limit_policy,
+       capabilities, base_billing_config, COALESCE(pricing_rule_set_id::text, ''), default_rate_limit_policy,
        COALESCE(runtime_policy_set_id::text, ''), runtime_policy_override
 FROM base_model_catalog
 WHERE ($1 <> '' AND id = NULLIF($1, '')::uuid)
@@ -384,6 +387,7 @@ LIMIT 1`, strings.TrimSpace(id), strings.TrimSpace(canonicalKey), strings.TrimSp
 		&item.DisplayName,
 		&capabilities,
 		&billingConfig,
+		&item.PricingRuleSetID,
 		&rateLimitPolicy,
 		&item.RuntimePolicySetID,
 		&runtimePolicyOverride,