fix(server): separate active subscriptions (#13077)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->

## Summary by CodeRabbit

* **Bug Fixes**
* Improved accuracy of subscription management by ensuring only active
or trialing subscriptions are considered in all relevant user,
workspace, and license actions.
* Enhanced consistency in subscription retrieval for workspace member
updates and subscription-related operations.

* **Refactor**
* Updated internal subscription retrieval methods to distinguish between
general and active subscriptions for more precise handling across the
app.

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

packages/backend/server/src/plugins/payment/manager/common.ts

@@ -84,9 +84,14 @@ export abstract class SubscriptionManager {
     subscription: KnownStripeSubscription
   ): Promise<void>;
 
+  abstract getActiveSubscription(
+    identity: z.infer<typeof SubscriptionIdentity>
+  ): Promise<Subscription | null>;
+
   abstract getSubscription(
     identity: z.infer<typeof SubscriptionIdentity>
   ): Promise<Subscription | null>;
+
   abstract cancelSubscription(
     subscription: Subscription
   ): Promise<Subscription>;