Merge branch 'phase/73-lesson-marks'

Co-authored-by: Cursor <cursoragent@cursor.com>

src/HSchool.People/LessonMarks.cs

@@ -0,0 +1,59 @@
+using HSchool.Content;
+
+namespace HSchool.People;
+
+/// <summary>One lesson mark (2–5). Sparse list on the person — not a year-long gradebook.</summary>
+public sealed class LessonMarkRecord
+{
+    public required string Subject { get; init; }
+
+    public required int Value { get; init; }
+
+    public required DateTime Time { get; init; }
+
+    public required int Period { get; init; }
+}
+
+/// <summary>Appends recent lesson marks and drops the oldest when over the BehaviorDef ceiling.</summary>
+public static class LessonMarkMemory
+{
+    public static bool Record(
+        Person person,
+        string subject,
+        int value,
+        DateTime time,
+        int period,
+        BehaviorDef rules)
+    {
+        ArgumentNullException.ThrowIfNull(person);
+        ArgumentNullException.ThrowIfNull(rules);
+        ArgumentException.ThrowIfNullOrWhiteSpace(subject);
+
+        if (rules.LessonMarkMax <= 0 || value is < 2 or > 5)
+        {
+            return false;
+        }
+
+        var list = person.LessonMarks;
+        if (list is null)
+        {
+            list = [];
+            person.LessonMarks = list;
+        }
+
+        list.Add(new LessonMarkRecord
+        {
+            Subject = subject,
+            Value = value,
+            Time = DateTime.SpecifyKind(time, DateTimeKind.Utc),
+            Period = period,
+        });
+
+        while (list.Count > rules.LessonMarkMax)
+        {
+            list.RemoveAt(0);
+        }
+
+        return true;
+    }
+}

src/HSchool.People/Roster.cs

@@ -75,6 +75,12 @@ public sealed record Person
     /// </summary>
     public List<OffenseRecord>? Offenses { get; set; }
 
+    /// <summary>
+    /// Recent lesson marks (2–5). Null when empty so people.json stays compact.
+    /// Ceiling and thresholds live on <c>BehaviorDef</c>.
+    /// </summary>
+    public List<LessonMarkRecord>? LessonMarks { get; set; }
+
     public int AgeOn(DateTime asOf) => SchoolYears.AgeYears(BirthDate, asOf);
 }