Export WAE QTC traffic to ADIF, and read it back

ADIF has no record for QTC traffic, which is why N1MM leaves it out and why
a WAE log cannot be moved between databases as ADIF. The plain export now
writes the contacts alone, as N1MM does: it used to write the QTC rows as
contacts, with the time of the traffic in RST_SENT and the reported callsign
in RST_RCVD.

File > Export > Export ADIF with QTC traffic writes the whole log instead.
A QTC row goes out with the station, time, band and mode, and the traffic in
application-defined fields — APP_NONEMM_QTC and friends, the prefix the ADIF
specification keeps for a program's own data — with the line in the comment
as well so the file can be read without this program. The report columns are
left off that record, because on a QTC row they hold the time and callsign
of the contact being reported. Reading such a file back rebuilds the rows,
so a WAE log survives the round trip whole. The item is only in the menu for
a contest with traffic.

Another program reading that file sees each QTC row as an ordinary contact
with the station the traffic was exchanged with and ignores the extra
fields. There is no way around that in ADIF, which is why the plain export
is still the one to hand over.

Contacts now also carry their row kind in APP_NONEMM_EXCHANGE1. Without it
a WAE log read back holds contacts with no kind at all, which N1MM's own
queries do not find.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0157i7PiZyqBkquxS9A6FTdQ

src/Nonemm.Contests/ContestLog.cs

@@ -41,6 +41,12 @@ public sealed class ContestLog
 
     public IReadOnlyList<Qso> Qsos => qsos;
 
+    /// The contacts alone. In WAE the log also holds QTC traffic, and a QTC
+    /// row is not a contact: its report columns hold the time and callsign of
+    /// the contact being reported. Anything that writes contacts out — the
+    /// ADIF export — takes these rather than every row.
+    public IEnumerable<Qso> Contacts => qsos.Where(contest.IsContact);
+
     public ScoreTally Tally => tally;
 
     /// The same score split the way N1MM's score window splits it: a row per