Handle no avatar, add delete avatar support

backend/internal/rest/handler_auth.go

@@ -50,7 +50,7 @@ func (h *Handler) signup(w http.ResponseWriter, r *http.Request) {
 
 	auth.SigninSetup(w, h.cfg.Cookies.SessionName, session.Token, session.ExpiresAt, h.cfg.Cookies.Secure)
 	h.refreshCsrf(w)
-	writeJson(w, http.StatusCreated, newUserResponse(u))
+	h.respondUser(w, r, u, http.StatusCreated)
 }
 
 func (h *Handler) signin(w http.ResponseWriter, r *http.Request) {
@@ -79,7 +79,7 @@ func (h *Handler) signin(w http.ResponseWriter, r *http.Request) {
 
 	auth.SigninSetup(w, h.cfg.Cookies.SessionName, session.Token, session.ExpiresAt, h.cfg.Cookies.Secure)
 	h.refreshCsrf(w)
-	writeJson(w, http.StatusOK, newUserResponse(u))
+	h.respondUser(w, r, u, http.StatusOK)
 }
 
 func (h *Handler) signout(w http.ResponseWriter, r *http.Request) {