Store User Attributes (firstname, surname, BPNL) in Keycloak Session for UI Profile Display

[jalvaro-lks]

Description

As a contributor,
I want the user's firstname, surname, and BPNL to be stored in the Keycloak session (e.g., included in the token or equivalent mechanism),
so that the UI can display this information in the profile icon without requiring hardcoded values.

Acceptance Criteria

• User attributes firstname, surname, and BPNL are stored in the Keycloak session or token upon login.
• The UI can retrieve these attributes dynamically from the session/token.
• No hardcoded profile data is required in the frontend; the profile icon displays the authenticated user's real information.

Additional Information

This feature aims to ensure that user-specific attributes are consistently available across the interface and reflect the Keycloak user configuration.