Programmable Notification Hub & Multi-Channel Alerting System

[SatyamPandey-07]

Objective: Replace hardcoded emails with a centralized "Notification Hub" that supports templates, user preferences, and multiple delivery channels (In-App, Email, Webhooks).

L3 Complexity: Involves building a provider-agnostic adapter pattern, a recursive template engine, and a persistence layer for alert history.

Files involved (9):
models/Notification.js
(New: Persistence)
models/NotificationPreference.js (New: User settings)
services/notificationService.js
(The Hub: Central logic)
services/notificationAdapters.js (New: Email/Webhook providers)
templates/notificationTemplates.js (New: Dynamic templating)
routes/notifications.js
(New: Preference & History API)
jobs/notificationQueue.js (New: Background retry logic)
middleware/notificationHydrator.js (New: Context gathering)
NOTIFICATION_HUB_DOCUMENTATION.md (Technical spec)

[github-actions]

Thank you for raising this issue!

We'll review it as soon as possible. We truly appreciate your contributions! ✨

Meanwhile make sure you've visited the README.md, CONTRIBUTING.md, and CODE_OF_CONDUCT.md before creating a PR for this. Also, please do NOT create a PR until this issue has been assigned to you. 😊