Paid-Only Newsletter Controls for Subscribers

🔍 Problem Statement

Subscribers cannot control which newsletters they receive based on their subscription tier. All newsletter options are visible to all users regardless of plan, and there is no way to restrict premium newsletters to paid subscribers — leading to unauthorised access or manual list management.

💡 User Story

As a publisher, I want to restrict certain newsletters to paid subscribers only and let subscribers manage their newsletter preferences based on their subscription tier, so that premium content stays gated and list management is automated.

🎯 Definition of Done (DoD)

A feature is done when:

✔️ Given a newsletter configured as paid-only, when a free user attempts to subscribe to it, then they are prompted to upgrade — and when a paid subscriber manages their preferences, then only newsletters available to their tier are shown as selectable.