Rework user types: create AuthenticatedUser and AnonymousUser class

Both are subclasses of an abstract User class which contains almost everything
interesting.

express/context.ts

@@ -5,10 +5,10 @@
 // needing to pass Call through every function.
 
 import { AsyncLocalStorage } from "node:async_hooks";
-import { AnonymousUser, type MaybeUser } from "./user";
+import { anonymousUser, type User } from "./user";
 
 type RequestContext = {
-    user: MaybeUser;
+    user: User;
 };
 
 const asyncLocalStorage = new AsyncLocalStorage<RequestContext>();
@@ -19,9 +19,9 @@ function runWithContext<T>(context: RequestContext, fn: () => T): T {
 }
 
 // Get the current user from context, or AnonymousUser if not in a request
-function getCurrentUser(): MaybeUser {
+function getCurrentUser(): User {
     const context = asyncLocalStorage.getStore();
-    return context?.user ?? AnonymousUser;
+    return context?.user ?? anonymousUser;
 }
 
 export { getCurrentUser, runWithContext, type RequestContext };