-- met_characters: which characters a user has already been introduced to.
-- Used by db_introductions.py / first_contact_instruction() so each character gives
-- a one-line self-introduction only on the very first turn with a given user.
--
-- Stored on user_profiles (keyed by id = user_id, the table that actually exists;
-- there is no public.users — auth users live in auth.users). It is deliberately NOT
-- added to TRACKED_FIELDS, so the profile classifier never reads or overwrites it;
-- db_introductions.py accesses it with its own targeted queries.

alter table public.user_profiles
    add column if not exists met_characters text[] not null default '{}';