Richer notifications (Start of agent message/permission required/plan approval needed) etc

[jonathanlab]

Currently our notificaitons only show "THREADNAME" needs your input

We should extend this to offer:

• The first part of the agent response if it finishes it's turn
• "THREADTITLE" : Permission needs your approval
• Plan needs your approval

etc.

https://posthog.slack.com/archives/C09G8Q32R6F/p1776780792479289