Adding modules

builder.AddRelatudeCMS()
    .AddApi()                                     // the CMS API, which serves the modules' commands
    .AddModule<VenuesModule>()
    .AddModule(new EventsModule { ParentPageId = homeId });

AddModule runs Configure at once, before the app is built. Services, settings and rendering options are added then; the rest waits for each database to start.
Adding a module twice adds it once, so a package and the host can both add it.
The name is letters, digits and -, starting with a letter, and unique on the site.
Dependencies must be added too, before or after. Modules run dependencies first, otherwise in the order added. A missing dependency or a circle stops the site at UseRelatudeCMS(), before any database opens.

Modules are never found by scanning assemblies, so Program.cs lists everything that runs.