Feature Request: Notifications

It would be nice to have the ability to get notifications from cabals/channels/mentions/etc if yous so choose. A sound and pop-up for when you're on another workplace, or if you're awaiting someone to get back to you etc.

Keep up the good work!

The issue names no files, tests, or entry points. Start by locating the cabal-cli event and terminal UI entry points, then clarify which channels, mentions, and workplaces should notify users and how opt-in settings work. Done should include an agreed notification scope and acceptance criteria for sound and pop-up behavior.

Written by the indexing model from the issue text.