add shel

src/HSchool.Content/Defs.cs

@@ -15,6 +15,7 @@ public enum DefKind
     BodyAttribute,
     Need,
     NameSet,
+    Subject,
 }
 
 /// <summary>Shared JSONC fields. Kind comes from the folder under <c>defs/</c>, not from the file.</summary>
@@ -64,8 +65,15 @@ public sealed class RoomDef : Def
     /// <summary>
     /// When true, a map room of this def with pupil slots becomes a roster class.
     /// Labs keep <see cref="ThingDef.PupilSlots"/> for lessons without forming a homeroom.
+    /// Homerooms are a seat count of <see cref="SeatThing"/>, not a table of named slots.
     /// </summary>
     public bool Homeroom { get; init; }
+
+    /// <summary>Thing whose <see cref="ThingDef.PupilSlots"/> × map seats is class capacity.</summary>
+    public string? SeatThing { get; init; }
+
+    /// <summary>Editor default when placing a new homeroom. Vanilla classrooms are 16.</summary>
+    public int DefaultSeats { get; init; }
 }
 
 public sealed class BuildingDef : Def;