Add 3 roles, settings for marathons

backend/app/schemas/game.py

@@ -32,7 +32,9 @@ class GameShort(BaseModel):
 class GameResponse(GameBase):
     id: int
     cover_url: str | None = None
-    added_by: UserPublic | None = None
+    status: str = "pending"
+    proposed_by: UserPublic | None = None
+    approved_by: UserPublic | None = None
     challenges_count: int = 0
     created_at: datetime