app_users (user_id, user_name, tz) records each user's home time zone as a tz database name such as 'Europe/Berlin'. user_logins (login_id, user_id, login_at) holds their logins; login_at is a TIMESTAMPTZ (an exact instant, shown in UTC).
For every login, return the wall-clock time and calendar date the user saw in their own time zone.
Columns: login_id, user_id, local_at (a TIMESTAMP without a time zone, e.g. 2024-07-01 09:00:00), local_date (a DATE). Sort by login_id.