Paint a WAE station by the traffic left with it, as N1MM does

N1MM has four colours for a station in WAE rather than the usual three, and
the manual and the RTTY tutorial both spell them out. Red is a new
multiplier, as everywhere else. Green is a new station with QTC traffic
still to exchange, which takes the more-than-one-multiplier colour because
WAE has no second multiplier to use it. Black is a station already worked
that still has traffic left — worth working for the QTC points alone — and
it is a colour of its own, N1MM's "Color of a QTC callsign in the WAE
contest". Grey is a dupe with nothing left, the same as in other contests.

The verdict carries how much traffic is left with the station, so the
callsign box, the check window, the bandmap and everything else that colours
a station say the same thing. The contest works the number out: ten with a
station on the other side of the contest, none with one on our own
continent, and none once the ten have gone. Every other contest answers
nought. The log counts the QTC rows per station as they are indexed rather
than counting them again for each station judged, because the bandmap judges
every spot it holds on every pass.

The verdict line says it in words as well, so a dupe reads `dupe · 7 QTCs
left` rather than `dupe`.

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

src/Nonemm.Contests/Rules/Wae.cs

@@ -86,6 +86,18 @@ public sealed class Wae : Contest
 
     public bool IsContact(Qso qso) => !WaeQtc.IsQtc(qso);
 
+    /// Ten QTC lines with any one station, for the whole contest and whatever
+    /// the band. Traffic goes between continents only: on CW and SSB that is
+    /// the same line the contest itself is drawn on, and on RTTY it is any two
+    /// continents that are not the same.
+    public int TrafficLeft(QsoContext qso, int exchanged)
+    {
+        bool between = mode == ModeCategory.Digital
+            ? qso.Continent.Length > 0 && qso.Continent != qso.Me.Continent
+            : IsWorkable(qso);
+        return between ? Math.Max(0, WaeQtc.MostPerStation - exchanged) : 0;
+    }
+
     /// One multiplier per band, worth more the lower the band. For a station in
     /// Europe it is the other station's country or call area; for a station
     /// outside it, the European country worked.