chore(lotw): log the record TQSL refused

'No QSOs processed' (exit 8) covers already-uploaded, out-of-certificate-
date-range, and a station callsign that does not match the location being
signed with -- TQSL's message does not say which. An operator whose QSO
was refused and then accepted after a round trip through another logger
is reporting a difference in the record itself, and the temp ADIF is
deleted the moment TQSL returns, so that difference could not be seen.

Logged on any non-zero exit: the record verbatim, the exit code and the
station location. It is QSO data; the key password is not logged.

internal/extsvc/lotw.go

@@ -265,6 +265,22 @@ func UploadLoTW(ctx context.Context, cfg ServiceConfig, tempDir, adifRecord stri
 	// callsign certificate's validity is silently left out, and reporting that as
 	// success stamped it sent for ever. TQSL says which case it is in its output,
 	// so the message is carried up rather than replaced with a guess.
+	if code != 0 && LogSink != nil {
+		// The ADIF that was handed to TQSL, verbatim, and how TQSL was called.
+		//
+		// TQSL says "no QSOs processed" for several unrelated reasons — already
+		// uploaded, outside the certificate's dates, or a STATION_CALLSIGN that
+		// does not match the station location it was told to sign with — and its
+		// message does not distinguish them. An operator whose contact was
+		// refused, then accepted after a round trip through another logger, is
+		// reporting a difference in THIS RECORD, and there is no way to see it
+		// afterwards: the temp file is deleted as soon as TQSL returns.
+		//
+		// Nothing secret here: it is a QSO, and the key password is not logged.
+		LogSink("lotw: tqsl exit %d for station location %q", code, loc)
+		LogSink("lotw: record was: %s", strings.TrimSpace(adifRecord))
+	}
+
 	switch code {
 	case 0:
 		return UploadResult{OK: true, Message: "uploaded to LoTW"}, nil