Fix client-side errors

frontend/src/stores/authStore.js

@@ -9,7 +9,6 @@ function getClaimsFromToken(token) {
     try {
         return jwtDecode(token);
     } catch (error) {
-        console.error('Invalid token:', error);
         return null;
     }
 }
@@ -27,7 +26,7 @@ export const useAuthStore = defineStore(
 
         const userId = computed(() => {
             const claims = getClaimsFromToken(accessToken.value)
-            return claims.sub;
+            return claims?.sub;
         })
 
         function updateTokens(data) {