Deferred from the XP/achievements launch lineup (docs/features/xp-levels/implementation-plan.md §1.6) — "definitely added later".
- Tiers: 1 / 3 / 7 / 12 / 20 competitions participated
- Backfill holder counts measured on production (base 7,004 players): 1465 / 439 / 60 / 8 / 0
- Adding it is the standard plug-in flow (docs/features/badges.md + docs/features/xp-levels/README.md §Achievements): BadgeType case, condition class, PlayerStatsSnapshot metric, translations
Deferred from the XP/achievements launch lineup (docs/features/xp-levels/implementation-plan.md §1.6) — "definitely added later".