Mean crud app in 4-5 hrs from now. No milestone until completed and no award until at least 1 hour of progress code is shown

No award until i can see some backend crud code and one angular service code No login needed, just create tree structure for adding and editing items. Thats it No ui needed just bootstrap components Logging in system i already have Must BE COMPLETED IN 4-5 hours from Now. I will test your knowledge first on TREE STRUCTURE and you will have to show me code developed before creating milestone. NO ui design needed JUST BOOTSTRAP BUTTONS AND TREE STRUCTURE Mean stack. All code must use express, mongoose , and angular 7. Angular cli. Code must be clean and commented Then you will show working code then payment will be made!! No payment until complete and no payment if not complete within 6-8 hours from now Requirements Create an application which will allow at least two users to log in simultaneously and manage items in categories. The categories should be in a hierarchy of potentially infinite depth. The items only require a label. The users should be able to perform standard CRUD, plus if one user makes a change, the other user(s) should see the change (if appropriate) without manually refreshing their web browser. Your solution should follow best practice, and be robust and scalable. We expect to see the same techniques and approaches that you would use in a real project. User journeys Mark wants to keep track of his belongings. He logs in, and is presented with a list of categories, showing the different levels visually. He adds “Electronics”, and under that, “Televisions”. To this category he adds the items “49-inch LCD”, “40-inch plasma”, and “32-inch CRT”. Sandy logs in and creates “Gaming consoles”, and under this, the items “PS4 Pro”, “XBox One X”, and “Nintendo Switch”. Mark sees Sandy’s entries appear. He edits “Gaming consoles” to sit under “Electronics”. This change appears on Sandy’s screen as soon as he has done it.