feat(progression): reward unique boss kills

design/user-stories/us-008-reward-spawn-progression.md

@@ -2,7 +2,7 @@
 type: User Story
 title: "US-008: Reward and encourage spawn progression"
 description: Remind players how to improve spawn access and reward each newly credited unique boss kill with an immediate cooldown reset.
-status: backlog
+status: done
 ---
 
 # US-008: Reward and encourage spawn progression
@@ -11,15 +11,15 @@ As a **player**, I want `/spawn` to explain how I can improve its cooldown and r
 
 ## Acceptance criteria
 
-- [ ] After every successful `/spawn`, a player who has not defeated all three unique qualifying enemies receives a reminder that defeating the remaining bosses permanently reduces the cooldown.
-- [ ] The reminder identifies the remaining eligible bosses and shows the next cooldown tier.
-- [ ] A player who has completed all three unique qualifying kills does not receive the progression reminder.
-- [ ] Each newly credited unique Warden, Ender Dragon, or Wither kill immediately clears the player's active `/spawn` cooldown.
-- [ ] Clearing the cooldown makes `/spawn` immediately available as a progression reward.
-- [ ] The newly credited kill also permanently applies the improved boss-based cooldown tier.
-- [ ] Repeated kills of an already credited enemy do not clear the cooldown.
-- [ ] The on-screen kill message states that `/spawn` is immediately available and displays the new cooldown tier.
-- [ ] Banned players cannot earn kill credit, a cooldown reset, or an improved tier.
+- [x] After every successful `/spawn`, a player who has not defeated all three unique qualifying enemies receives a reminder that defeating the remaining bosses permanently reduces the cooldown.
+- [x] The reminder identifies the remaining eligible bosses and shows the next cooldown tier.
+- [x] A player who has completed all three unique qualifying kills does not receive the progression reminder.
+- [x] Each newly credited unique Warden, Ender Dragon, or Wither kill immediately clears the player's active `/spawn` cooldown.
+- [x] Clearing the cooldown makes `/spawn` immediately available as a progression reward.
+- [x] The newly credited kill also permanently applies the improved boss-based cooldown tier.
+- [x] Repeated kills of an already credited enemy do not clear the cooldown.
+- [x] The on-screen kill message states that `/spawn` is immediately available and displays the new cooldown tier.
+- [x] Banned players cannot earn kill credit, a cooldown reset, or an improved tier.
 
 ## Related