Also looks like I spoke too soon - regarding your original question 1, if I bypass nginx and connect directly using the server external ip to port 4567, I can see nodebb launch "correctly". But if I access it through the domain name, it gives me the above result. So that did matter.
Here is the nginx server block (file name - forum.kado.ai.conf)-
Here is the nodebb config file.
I am working on a web app where users can discuss a document (see the prototype here; I am in the process of simplifying the UX and planning for version 1). The UI looks like this:
-- a main area shows the document,
-- in other areas/windows/tabs, users can create topics to discuss parts of the document.
Does it sound feasible with nodeBB? My main concern is not OAuth/SSO, but client-side display.