feat(SNNBot): fire only when aim is locked on target

Bot now conserves ammo by firing only when aimLocked=true (error < 1.5°).
During WAITING phase, checks aimLocked flag before firing FIRE_POWER; calls
setFire(0.0) when not locked. Prevents wasted shots on moving targets.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

SNNBot_garage/src/SNNBot.nim

@@ -385,7 +385,10 @@ method run*(bot: SNNBot) =
 
     of WAITING:
       aimTo(bot.targetAngle, gunDir)
-      discard setFire(FIRE_POWER)
+      if bot.aimLocked:
+        discard setFire(FIRE_POWER)
+      else:
+        discard setFire(0.0)
       let err = abs(normalizeRelativeAngle(bot.targetAngle - gunDir))
       if err < AIM_TOL:
         bot.phase = EVALUATE