Исправлены ошибки Wild Card и skip-assignment

- Wild Card: исправлен game.name → game.title
- Wild Card: добавлена поддержка игр типа playthrough
- points.py: добавлена проверка на None для challenge_points
- PlaythroughInfo: поля сделаны Optional (description, points, proof_type)
- organizer_skip_assignment: добавлен фильтр is_event_assignment

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/app/api/v1/marathons.py

@@ -1049,7 +1049,7 @@ async def organizer_skip_assignment(
     if not participant:
         raise HTTPException(status_code=404, detail="Participant not found")
 
-    # Get active assignment
+    # Get active assignment (exclude event assignments)
     result = await db.execute(
         select(Assignment)
         .options(
@@ -1059,6 +1059,7 @@ async def organizer_skip_assignment(
         .where(
             Assignment.participant_id == participant.id,
             Assignment.status == AssignmentStatus.ACTIVE.value,
+            Assignment.is_event_assignment == False,
         )
     )
     assignment = result.scalar_one_or_none()