Update auth.ts to return user info for storage from Keycloak

[linear]

Description:

In order to populate the user management table, we will need to extract some of the information that is returned from Keycloak and load it into the table. As such, we need to return user credentials for storage, potentially leveraging Auth.js database adapter, and create a session, likely with database.

A follow up ticket will actually add the retrieved user info to the database. The scope of this ticket is only for retrieval.

Acceptance Criteria:

• When a user authenticate via Keycloak, their username/email is retrieved

[linear]

QUE-126 Update `auth.ts` to return user info for storage from Keycloak