Add opinions storage, morning drift, and Connections card tab.

src/HSchool.People/Roster.cs

@@ -52,6 +52,9 @@ public sealed record Person
     /// <summary>Changing-room node when this pupil won a locker slot. Null for staff and the rest.</summary>
     public string? LockerRoomId { get; init; }
 
+    /// <summary>What this person thinks of others, A→B. Sparse; zero is not stored.</summary>
+    public IReadOnlyDictionary<string, int> Opinions { get; init; } = new Dictionary<string, int>(StringComparer.Ordinal);
+
     public int AgeOn(DateTime asOf) => SchoolYears.AgeYears(BirthDate, asOf);
 }