Show director summons as info toasts and presence queue labels.

Corridor waiters need a summon-phase byte on presence (v11); EventDef DirectorSummoned is info-only so clocks keep running.

src/HSchool.Simulation/WorldEvent.cs

@@ -2,5 +2,6 @@ namespace HSchool.Simulation;
 
 /// <summary>
 /// A fact the school raised this step. Same seam as <c>AffinityEvent</c>: a list, no UI.
+/// <see cref="PersonKey"/> is empty when the fact is school-wide (morning, lesson bell).
 /// </summary>
-public readonly record struct WorldEvent(string Trigger);
+public readonly record struct WorldEvent(string Trigger, string PersonKey = "");