Read the rest of what a .udc file says, and score what N1MM scores

Two pieces of work on the scoring engine.

The .udc reader now takes N1MM's published scoring vocabulary: the full
PointsPerContact condition set, the PointsMultBy family, PowerMult, BonusPoints,
the multiplier sources and the settings that say which stations bring a
multiplier in. MultMult is a weight rather than a switch, as in N1MM's
ComputeScore. The entry categories and the sent exchange reach the rules in a
new ContestEntry, so a contest can score by the power category it is entered in
or by what this station sends.

Then every contest in a real N1MM log was scored again from these rules and
compared with the points and multiplier flags N1MM wrote. That found five bugs:
ARRL DX and IARU read the exchange from the wrong column, a stored " " was read
as a value rather than as empty, CQ WW RTTY's own Canadian area names were not
counted, a maritime mobile scored nothing, and a contact in a mode the contest
does not run scored as if it were in the contest.

docs/n1mm-interop.md has the check and what still differs.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RoGtneMQaz4M9w7Kk49AVD

src/Nonemm.Contests/Rules/Sweepstakes.cs

@@ -44,7 +44,7 @@ public sealed class Sweepstakes : Contest
         return ArrlSections.IsSection(section) ? [new Multiplier(1, section, "")] : [];
     }
 
-    public int TotalScore(ScoreTally tally) => tally.Points * tally.TotalMultipliers;
+    public int TotalScore(ScoreTally tally, ContestEntry entry) => tally.Points * tally.TotalMultipliers;
 
     /// Sweepstakes puts the callsign after the serial number and precedence
     /// rather than first, which is why the writer takes the whole column list.