[Feature Request]: Discord webhook notification (batch summary)

The request

Add optional support for sending update results to a Discord channel via a Webhook.

Instead of posting one notification per app (which would flood the channel with dozens of messages during a run), send a single summary message at the end of each update cycle. The summary should list how many apps were updated, skipped, and failed - ideally including the app names.

It should be configurable (for example a WAU_DiscordWebhookURL setting) with a notification level similar to the existing notification system: send always, only when there are errors, or never.

This would help, like for example if I'm away from the system when the update triggers, so I know what happened, or if I choose to let it update midnight, so I'd like to be informed about what apps updated.

if this is possible to add then thank you so much.

Is your feature request related to a problem?

Just found this one, and set it up, I had issues before, because I use Dockhand to manage and update docker containers, at some point there was an update that broke a container, and I didn't know about it, so I added the Dockhand Discord Webhook, and I like doing this on all of these auto update projects.

Additional information

No response

Start by locating the existing notification system and the entry point for the update cycle. Trace how update results are collected and how notification settings are read. Done means an optional Discord webhook can send one configurable summary per cycle, with updated, skipped, and failed apps represented at the selected notification level.