Enhance school day structure and decision-making for lunch breaks

- Updated `ai.md` to clarify the mechanics of hunger restoration and the importance of lunch breaks in the school schedule.
- Revised `schedule.md` to detail the new lunch break structure, allowing for separate sittings for different grade levels.
- Enhanced `Decision.cs` and `DecisionPlanner.cs` to incorporate logic for lunch breaks, ensuring that students only leave lessons during their designated lunch windows.
- Updated `DayFrameDef` and related classes to support multiple lunch breaks and validate their configurations.
- Adjusted tests to validate the new decision-making logic regarding lunch breaks and hunger management, ensuring robust functionality.
- Improved localization strings to reflect changes in the school day structure and lunch functionalities.

src/HSchool.Simulation/PresenceSystem.cs

@@ -375,6 +375,9 @@ internal static class PresenceSystem
         var bound = Duty.IsOtherStaff(person)
             ? slot.Kind != DaySlotKind.Outside
             : slot.Kind == DaySlotKind.Lesson && lessons.Any(lesson => lesson.Period == slot.Index);
+        var frame = school.Catalog!.DayFrame;
+        var lunchOpen = frame is not null
+            && SchoolDay.IsLunchWindow(frame, slot, ClassOf(school, person)?.Year);
         var state = new ActorState(
             presence.NodeId,
             presence.DestinationId,
@@ -386,7 +389,8 @@ internal static class PresenceSystem
             bound,
             duty,
             needs.Values,
-            intent);
+            intent,
+            lunchOpen);
         var decision = DecisionPlanner.Decide(
             school.Catalog!,
             school.Map!,