Add freemium variant C: archetype persistence, dashboard banner, lesson gate

- User.archetype/utmSource/utmMedium/utmCampaign fields + migration
- register flow reads ?archetype/?utm_* and saves them on the User row
- dashboard ArchetypeBanner: per-archetype 'твой путь' block
- lesson gate after wow-moment lesson (WOW_MOMENT_LESSON_ID=obs-start-l2-006) → tripwire + full-course offer

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

prisma/migrations/20260623060000_add_user_archetype_utm/migration.sql

@@ -0,0 +1,5 @@
+-- Тип второго мозга из freemium-квиза + UTM-метки для персонализации воронки
+ALTER TABLE "User" ADD COLUMN "archetype" TEXT;
+ALTER TABLE "User" ADD COLUMN "utmSource" TEXT;
+ALTER TABLE "User" ADD COLUMN "utmMedium" TEXT;
+ALTER TABLE "User" ADD COLUMN "utmCampaign" TEXT;