Write basic node.js web app for real-time collaboration on text documents

We want to obtain a basic node.js web app which has similarities to [login to view URL] and [login to view URL] . The app should make it possible for academics to work collaboratively and in real-time on papers or other scientific work. The frontend can be left aside, we are just interested in backend here. Specifically, we need to have 1. a landing page, with authentication (login /signup), also social login, and some pages like pricing and contact ([login to view URL] is a good reference for all of this here). 2. after login a basic site covering all documents created so far plus a panel to create new ones (similar to [login to view URL] in the attachment) 3. also we have another site, which can be selected at the top, where all users are covered, with which one is connected to. Here, you should have a search function to find the right colleage, based on name, institution or e-mail. Also. some siggestions should be made based on the network of connections or based on the institution or the field of study. 4. An elementary chat function between the contacts would be nice, but not a must at this point. 5. Also there is a panel on the far right, with your own icon, and when you click on it you can logout then or you reach the account panel (similar to [login to view URL] in the attachment)..Here, you can set your icon and configure other things. Also you can delete your account, manage your social media connections for authentication, and handle the payment process. 6. When creating a new document (see 2.) you first have a popup where you enter perhaps the name of the document, but more importantly the collaborators (no matter if from your contact list or not, and if people are not on the platform one can send an invite e-mail) 7. After document creation you are forwarded to a text editor like Etherpad ([login to view URL]) or Quill ([login to view URL]), such that you can do all the fancy stuff like real-time collaborative editing (seeing the cursors would be cool), comments on parts and perhaps a chat function per document (but that would be optional). Furthermore, you have a panel at the top where you can select between different localhost apis (based on the pricing regime one can select no/a few/or many). When you have selected one, you can type and the last couple of words are send to an API and a predcition for the next words is made. Thiis should appear in grey in the text and once you press TAB the text is incorporated, if you just continue typing the prediction does not matter. Alternatively, the top 5 predictions are listed below and you can choose from the best one with up and down. 8. The payment has to be implemented with paddle (perhaps this here [login to view URL] helps) 9. The web app should be dockerizable, so a Dockerfile should be provided and some docker-compose file with nginx and the database etc. covered. 10. Sign In and sign up should also be possible at least with Google and Facebook and E-Mails should also be connnected. Furthermore, at various positions E-Mails should be sent, for instance, when I are invited to the platform, when a document is created and you are collaborator, when somebody invites you as a contact or somebody accepted your contact request or you are mentioned in a comment of a document. Of course, all standards regarding data security have to be met. Furthermore, we just want to use code that is distributed under permissive license. Since the description here is very clear, we do not accept renegotations of price. You make a bid, that is okay, but we do not accept if you extend your payment expectation beyond your bid in the proposal.