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.

tests/HSchool.Content.Tests/VanillaCoreTests.cs

@@ -71,7 +71,11 @@ public class VanillaCoreTests
         Assert.Equal("Hunger", catalog.Actions["EatLunch"].Need);
         Assert.Equal(0.5f, catalog.Actions["EatLunch"].NeedGain);
         Assert.Equal("SchoolYard", catalog.Actions["WalkYard"].Room);
-        Assert.Equal(0.1f, catalog.Needs["Hunger"].DecayPerHour);
+        // Hunger falls fast enough to be felt inside one school day and, like sleep, comes back
+        // off campus — people eat at home. Before that pair of numbers the school went hungry and
+        // never recovered: half of it sat below the urgency threshold permanently.
+        Assert.Equal(0.2f, catalog.Needs["Hunger"].DecayPerHour);
+        Assert.True(catalog.Needs["Hunger"].RestoredOffCampus);
         Assert.True(catalog.Needs["Sleep"].RestoredOffCampus);
         Assert.NotNull(catalog.BehaviorRules);
         Assert.Equal(0, catalog.BehaviorRules.CommuteSlackMin);