fix: set content-type to json

internal/auth/routes.go

@@ -137,6 +137,8 @@ func (h *AuthHandler) refreshToken(w http.ResponseWriter, r *http.Request) {
 
 	encoder := json.NewEncoder(w)
 
+	w.Header().Set("Content-Type", "application/json")
+
 	if err := encoder.Encode(Response{
 		AccessToken:  access,
 		RefreshToken: refresh,
@@ -213,6 +215,11 @@ func (h *AuthHandler) login(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
+	if err := h.repo.UpdateLastLogin(r.Context(), user.ID); err != nil {
+		web.Error(w, "failed to update user's last login", http.StatusInternalServerError)
+		return
+	}
+
 	encoder := json.NewEncoder(w)
 
 	type Response struct {