[Merged] Reflect Extended Subscription End Date on Subscription Details Page

[Merged into Add Feature to Adjust Subscription Start/End Date (Platform + API)]

🔍 Problem Statement

When a subscription's end date is extended (e.g. via a complimentary period or manual adjustment), the updated end date is not reflected on the Subscription Details page. Admins must check the API to verify the actual expiry, which is confusing and error-prone.

💡 User Story

As a Pelcro admin, I want the Subscription Details page to show the extended end date when it has been modified, so that I can confirm the correct access period at a glance.

🎯 Definition of Done (DoD)

A feature is done when:

✔️ Given a subscription whose end date has been extended, when an admin views the Subscription Details page, then the extended end date is displayed clearly — distinguishing it from the original billing cycle end date.