Regenerate "Cómo te veo" (at most once every 12 hours)

Recomputes the facts (reply times per relationship family, unanswered threads, patterns on the user's side, traits, sent messages) and asks the model to write the portrait from them. Skips the model when the facts did not change since the last generation (reason: "unchanged") or when there is no data at all (reason: "insufficient_data").