feat(fixer): add timed combat boost

design/user-stories/us-006-use-fixer-abilities.md

@@ -2,7 +2,7 @@
 type: User Story
 title: "US-006: Use Fixer abilities"
 description: Give the Fixer a periodic offensive and health enhancement strengthened near the Tyrant.
-status: backlog
+status: done
 ---
 
 # US-006: Use Fixer abilities
@@ -11,13 +11,13 @@ As the **Fixer**, I want a substantial temporary combat boost so that I can prot
 
 ## Acceptance criteria
 
-- [ ] The Fixer can activate ten minutes of Strength and Health Boost once per rolling hour using the named Fixer ability item.
-- [ ] Normal activation provides two total rows of hearts when combined with the player's normal maximum health.
-- [ ] Activation in the same world and within the configured Tyrant range provides three total rows of hearts.
-- [ ] Proximity is evaluated when the ability is activated and does not alter the active tier afterward.
-- [ ] Health is safely clamped when the boost expires, is suppressed, or changes tier.
-- [ ] The cooldown uses unpaused elapsed time and survives death, logout, and restart.
-- [ ] The player can inspect the remaining cooldown and receives clear feedback when activation is unavailable.
+- [x] The Fixer can activate ten minutes of Strength and Health Boost once per rolling hour using the named Fixer ability item.
+- [x] Normal activation provides two total rows of hearts when combined with the player's normal maximum health.
+- [x] Activation in the same world and within the configured Tyrant range provides three total rows of hearts.
+- [x] Proximity is evaluated when the ability is activated and does not alter the active tier afterward.
+- [x] Health is safely clamped when the boost expires, is suppressed, or changes tier.
+- [x] The cooldown uses unpaused elapsed time and survives death, logout, and restart.
+- [x] The player can inspect the remaining cooldown and receives clear feedback when activation is unavailable.
 
 ## Related