chore: remove compile warning and apply fallback for addon active_from

Author: tothandras

api/spec/packages/aip/src/subscriptions/subscriptionaddon.tsp

@@ -6,6 +6,7 @@ namespace Subscriptions;
  * SubscriptionAddon represents an association between a subscription and an add-on,
  * controlling which add-ons are available for purchase within a subscription.
  */
+#suppress "@openmeter/api-spec-aip/repeated-prefix-grouping" "active_from and active_to are standard AIP temporal fields"
 @friendlyName("SubscriptionAddon")
 model SubscriptionAddon {
   ...Shared.Resource;

api/v3/handlers/subscriptions/subscriptionaddons/convert.go

@@ -45,7 +45,7 @@ func ToAPISubscriptionAddon(a subscriptionaddon.SubscriptionAddon) (apiv3.Subscr
 		Labels:      labels.FromMetadata(a.Metadata),
 		Quantity:    inst.Quantity,
 		QuantityAt:  now,
-		ActiveFrom:  *union.From,
+		ActiveFrom:  lo.FromPtrOr(union.From, now),
 		ActiveTo:    union.To,
 	}, nil
 }