Add AI parent meetings after a class last lesson.

Class teachers rarely keep the homeroom; invited parents walk onto the map, opinions nudge, then parents leave OffCampus. No player schedule API.

src/HSchool.People/Seed.cs

@@ -23,6 +23,8 @@ public static class Seed
     public const int HomeSalt = 15;
     public const int SummonSalt = 16;
     public const int HealthSalt = 17;
+    public const int MeetingSalt = 18;
+    public const int MeetingAttendSalt = 19;
 
     /// <summary>A stream that belongs to the school rather than to one family.</summary>
     public static int ForSchool(int schoolSeed, int salt) => Mix(schoolSeed, familyIndex: -1, salt);