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/schema.prisma

@@ -25,6 +25,10 @@ model User {
   banExpires    DateTime?
   comment       String?
   mustChangePassword Boolean @default(false)
+  archetype     String?   // тип второго мозга из квиза: architect|gardener|librarian|pragmatist
+  utmSource     String?
+  utmMedium     String?
+  utmCampaign   String?
   createdAt     DateTime  @default(now())
   updatedAt     DateTime  @updatedAt