I took a look at the new designs and it looks like we are on the right track.
Can you ensure the notification bell icon is always visible on narrow screens? From the design it's not clear. I fear you may be thinking to show it only when the menu is accessed, which is not great, it should be always accessible.
I reviewed and tested your code, I think during next week we have to achieve the following:
Once we have the above you can start registering the menu groups for the other modules and then with the notification widget.
So far so good, it seems like a lot was done, but not much merged yet, so let's start to fill the "Done" column of your board by merging some PRs and then let's move on quickly to the next points.