Feature Request: Notification overview

### What

(generated with Gemini)

I would like to have a place, where all notifications are shown.

### Why

The normal comment notifications only show the number of comments that need to be published. I don't want to control every like. But it would be nice to see new likes somewhere. So I can see who liked/shared/commented which post.

### How

As these reactions are tied to the user's account, it might be best to add this to the user menu like in the screenshot.

An then there could be a more detailed overview:
(generated with Gemini)

Start by reviewing the existing comment-notification flow and the user-menu entry point described in the issue. Define how likes, shares, and comments should appear for the signed-in user, then verify that the overview identifies who reacted and which post they interacted with.

Written by the indexing model from the issue text.