Address PR review: graceful shutdown, Role/NewUser, drop SQLite.

internal/web/auth.go

@@ -88,16 +88,22 @@ func (s *Server) handleRegister(w http.ResponseWriter, r *http.Request) {
 		http.Error(w, "could not save password", http.StatusInternalServerError)
 		return
 	}
-	asAdmin := false
+	role := store.RoleUser
 	if s.cfg.AdminUsername != "" && store.NormalizeUsername(username) == store.NormalizeUsername(s.cfg.AdminUsername) {
 		n, err := s.store.CountAdmins(r.Context())
 		if err != nil {
 			http.Error(w, "could not create account", http.StatusInternalServerError)
 			return
 		}
-		asAdmin = n == 0
+		if n == 0 {
+			role = store.RoleAdmin
+		}
 	}
-	u, err := s.store.CreateUser(r.Context(), username, string(hash), asAdmin)
+	u, err := s.store.CreateUser(r.Context(), store.NewUser{
+		Username:     username,
+		PasswordHash: string(hash),
+		Role:         role,
+	})
 	if err != nil {
 		p.Error = "That username is taken."
 		s.exec(w, "register", p)