Do not change renewal type to manual renewal when a subscription is cancelled

🔍 Problem Statement
As a Pelcro admin, I experience auto-renewal subscriptions being automatically changed to manual renewal when cancelled, which breaks fulfillment logic and causes downstream systems to process cancelled auto-renewals incorrectly.

💡 User Story
As an admin, I want a cancelled subscription's renewal type to remain unchanged, so that fulfillment and reporting accurately reflect how the subscription was originally sold.

🎯 Definition of Done
- Given an auto-renewal subscription, when it is cancelled, then the renewal type is NOT changed to manual renewal.
- This change impacts the API (subscription cancellation endpoint) and backend subscription lifecycle logic.
- Limitations: applies to both admin-initiated and subscriber-initiated cancellations.

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Problem Statement Currently, when an auto-renewal subscription is cancelled , Pelcro automatically changes the renewal type from Auto-Renewal to Manual Renewal . This behavior causes downstream issues, particularly with fulfillment logic , because cancelled subscriptions are no longer represented accurately based on how they were originally sold and paid for. As a result, eligible customers are excluded from fulfillment lists , even when they are still entitled to receive issues already covered by payment. Definition of Done (DoD) Renewal type remains unchanged when a subscription is cancelled. Cancellation only affects: Subscription status Renewal behavior (future billing)