I’d love to be wrong, and hopefully it’s still being worked on. But I don’t think Rhino Inside supports Grasshopper yet. Just Rhino Common.
Neither Grasshopper, rhinoscriptsyntax, scriptcontext nor ghpythonlib is in globals or sys.modules when I ran rhinoinside.load() just now at least, and I can’t find an announcement about Grasshopper support in the main thread. Rhino inside Python