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.Simulation.Tests/SchoolNamesTests.cs

@@ -0,0 +1,81 @@
+namespace HSchool.Simulation.Tests;
+
+/// <summary>
+/// What used to be checked through <c>SchoolRegistry</c>. The registry is gone — the server gives
+/// every school its own worker — but the name and start-date rules it guarded are still the ones
+/// the create endpoint applies.
+/// </summary>
+public class SchoolNamesTests
+{
+    [Theory]
+    [InlineData(null)]
+    [InlineData("")]
+    [InlineData("   ")]
+    [InlineData("\u0009\u000A")]
+    public void BlankNames_AreRejected(string? name)
+    {
+        Assert.False(SchoolNames.TryNormalize(name, out _));
+    }
+
+    [Fact]
+    public void OverlongNames_AreRejected()
+    {
+        Assert.False(SchoolNames.TryNormalize(new string('ш', School.MaxNameLength + 1), out _));
+        Assert.True(SchoolNames.TryNormalize(new string('ш', School.MaxNameLength), out _));
+    }
+
+    [Fact]
+    public void SurroundingSpaceAndControlCharacters_AreStripped()
+    {
+        Assert.True(SchoolNames.TryNormalize("  Лицей  ", out var normalized));
+        Assert.Equal("Лицей", normalized);
+    }
+
+    [Fact]
+    public void StartDatesOutsideTheSupportedRange_AreRejected()
+    {
+        Assert.False(GameClock.IsValidStartDate(new DateTime(1500, 1, 1, 0, 0, 0, DateTimeKind.Utc)));
+        Assert.False(GameClock.IsValidStartDate(new DateTime(3200, 1, 1, 0, 0, 0, DateTimeKind.Utc)));
+        Assert.True(GameClock.IsValidStartDate(new DateTime(2012, 4, 3, 6, 0, 0, DateTimeKind.Utc)));
+    }
+
+    [Fact]
+    public void SuggestedNames_AreUsableAndNeverRepeatATakenOne()
+    {
+        var generator = new SchoolNameGenerator(new Random(1234));
+        var taken = new List<string>();
+
+        for (var i = 0; i < 20; i++)
+        {
+            var suggestion = generator.Next(taken, SchoolNameLanguage.Russian);
+            Assert.True(SchoolNames.TryNormalize(suggestion, out _), $"\"{suggestion}\" is not a usable name.");
+            Assert.DoesNotContain(suggestion, taken, StringComparer.OrdinalIgnoreCase);
+            taken.Add(suggestion);
+        }
+    }
+
+    [Fact]
+    public void SuggestedNames_FitTheNameLimitInBothLanguages()
+    {
+        var generator = new SchoolNameGenerator(new Random(1234));
+
+        foreach (var language in new[] { SchoolNameLanguage.Russian, SchoolNameLanguage.English })
+        {
+            for (var i = 0; i < 200; i++)
+            {
+                Assert.InRange(generator.Next([], language).Length, 1, School.MaxNameLength);
+            }
+        }
+    }
+
+    [Fact]
+    public void SuggestedEnglishNames_AreAscii()
+    {
+        var generator = new SchoolNameGenerator(new Random(1234));
+
+        for (var i = 0; i < 50; i++)
+        {
+            Assert.Matches("^[A-Za-z0-9 .]+$", generator.Next([], SchoolNameLanguage.English));
+        }
+    }
+}