-- Owner defaults: recurring per-user picks that were previously re-sent on
-- every request. All nullable — NULL = keep the current per-request /
-- hard-default behavior.
ALTER TABLE user_ai_prefs ADD COLUMN default_model TEXT;
ALTER TABLE user_ai_prefs ADD COLUMN default_backend TEXT;
ALTER TABLE user_ai_prefs ADD COLUMN default_persona_id TEXT;
ALTER TABLE user_ai_prefs ADD COLUMN reel_span TEXT;
ALTER TABLE user_ai_prefs ADD COLUMN reel_max_segments INTEGER;