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/SchoolNames.cs

@@ -0,0 +1,28 @@
+namespace HSchool.Simulation;
+
+/// <summary>
+/// The rules a school name has to pass. A name arrives from a browser, so it is trimmed and
+/// stripped before anything stores it.
+/// </summary>
+public static class SchoolNames
+{
+    /// <summary>Trims, strips control characters and enforces the length limit.</summary>
+    public static bool TryNormalize(string? name, out string normalized)
+    {
+        normalized = string.Empty;
+
+        if (string.IsNullOrWhiteSpace(name))
+        {
+            return false;
+        }
+
+        var cleaned = new string(name.Where(character => !char.IsControl(character)).ToArray()).Trim();
+        if (cleaned.Length == 0 || cleaned.Length > School.MaxNameLength)
+        {
+            return false;
+        }
+
+        normalized = cleaned;
+        return true;
+    }
+}