feat: add PostgreSQL support and enhance evaluation loading

- Added `pg` and `@types/pg` dependencies for PostgreSQL integration.
- Updated `useEvaluation` hook to load user evaluations from the API, improving data management.
- Refactored `saveUserEvaluation` and `loadUserEvaluation` functions to interact with the API instead of localStorage.
- Introduced error handling for profile loading and evaluation saving to enhance robustness.
- Added new methods for managing user profiles and evaluations, including `clearUserProfile` and `loadEvaluationForProfile`.

services/client.ts

@@ -0,0 +1,4 @@
+// Client-side services only
+// Safe to import in React components and hooks
+
+export { ApiClient, apiClient } from "./api-client";