I do something similar. Where is always seems to fall apart is with things I collaborate on with others. Sometimes, joint projects get their own home (i.e., they become an organization, or at least get their own public repository of some sort). So in addition to "inbox" "media" and "private" (my version of "vault") I've also got a "shared" category.
It's still not perfect, because ultimately the subcategories of "shared" need to actually be accessible, or mirrored, or it's not actually true. And sometimes, a project goes into "shared" aspirationally, even if I have no collaborators yet, as a subtle reminder that I might share it someday, so I don't want to put anything in that folder that I'm not comfortable being public or semi-public.
It's still not perfect, because ultimately the subcategories of "shared" need to actually be accessible, or mirrored, or it's not actually true. And sometimes, a project goes into "shared" aspirationally, even if I have no collaborators yet, as a subtle reminder that I might share it someday, so I don't want to put anything in that folder that I'm not comfortable being public or semi-public.