docs: note the spam-safety invariant on AITimer.Prod

A prodded think grants reaction, not action: steps are gated by the NextMove
budget, swings/casts/abilities/detect-hidden by their own timers, and each
command yields at most one think with no compounding. Verified against RunUO,
which granted zero extra thinks (change-guarded CurrentSpeed -> random 0-1s
timer restart) but also no action-rate advantage, for the same reason.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Projects/UOContent/Mobiles/AI/BaseAI/AITimer.cs

@@ -54,6 +54,9 @@ public sealed class AITimer : Timer
 
     // A fresh command must not wait out the previous cadence: think now. Pets are exempt
     // from sector deactivation, so dropping the stagger Delay here cannot bunch sector wakes.
+    // Spam-safe: at most one think per command and no compounding, and a think grants no
+    // action — steps (NextMove budget), swings, casts, abilities and detect-hidden are all
+    // gated by their own budgets/timers that this never touches.
     public void Prod()
     {
         _nextThink = Core.TickCount;