forked from UKSOURCE/cms.lams
Introduce a centralized system to manage all website form submissions and newsletter subscriptions. - Add `Submission` and `NewsletterSubscription` models with MongoDB schema validation - Implement `submissionController` and `newsletterSubscriptionController` for CRUD operations and filtering - Create a unified admin UI for reviewing submissions across different sources (home, request, contact, partnership, newsletter) - Add database migration scripts for creating collections and indexes - Refactor partnership inquiry forms to use a fixed field structure - Update admin navigation and server CORS settings to support PATCH requests