Notification Server

[nikkothari22]

We need a notification relay server that is tailored to Raven's use case.

1. Topic based notifications for channels work, but also send notifications to the sender of the message. Notifications are shown for messages sent by the sender in channels #813 and Notifications - too many #1274
2. We would like users to be able to decide which kinds of notifications they would want to receive on which device (phone vs laptop). This can only be done if we store notification tokens on the site instead of on the relay.
3. For privacy, it's best to not store any user information on the relay server. Since user ID's are defaulted to email addresses in Frappe, we cannot store user IDs on the relay server - instead the relay server should just have an API to take in the list of FCM tokens and the message content - this makes it completely anonymous. We can set pricing plans based on max number of devices the notification is sent to instead of users.

To implement this:

• Store notification tokens on the site with device information. Make it backwards compatible with Frappe Cloud's notification relay server. #1319
• Create a new Frappe app for the relay service
• Allow users to switch between notification services: Frappe Cloud and Raven's relay service.

[linear]

RAV-99 Notification Server