fix: a watched callsign is never parked; refuse uploads to unconfigured services

ZD8GB — watch-listed, six streams a period, two of them RR73 — was
refused as "parked" for the rest of the session. Parking answers "it
will not answer, stop wasting the evening on it", which is a fair verdict
about a station the LOG picked out and the wrong one about a station the
OPERATOR named: a DXpedition running a pileup takes more than two series
of calls to get through to, which is exactly why it is on the list. The
rest between series still applies, so it cannot monopolise the
transmitter — it simply never becomes ineligible.

Send to (right-click) now refuses a service with no credentials and says
which are missing. The upload runs on its own goroutine and reports into
the QSL Manager's console, which is not open when the command came from
the QSO list, so an upload to an unconfigured service looked exactly like
one that worked. The toast is also raised only once the backend has
accepted the request, and Cloudlog / Wavelog and HamQTH name themselves
in it.

internal/autocall/autocall.go

@@ -1000,7 +1000,19 @@ func (e *Engine) judge(c Candidate, p Period, only []string) (bool, string) {
 	if rank(c) == 0 {
 		return false, "nothing-needed"
 	}
-	if e.rounds[call] >= e.set.MaxRounds {
+	// A WATCHED callsign is never parked.
+	//
+	// Parking is the answer to "it will not answer, stop wasting the evening on
+	// it" — a fair verdict about a station the LOG picked out, and the wrong one
+	// about a station the OPERATOR did. A DXpedition running a pileup takes more
+	// than two series of calls to get through to, which is precisely why it was
+	// put on the list; watched ZD8GB was refused for the rest of the session
+	// after fourteen unanswered calls, while it went on transmitting six streams
+	// a period.
+	//
+	// The rest between series still applies, so it does not monopolise the
+	// transmitter — it simply never becomes ineligible.
+	if e.rounds[call] >= e.set.MaxRounds && !c.Watched {
 		return false, "parked" // its series are spent for the session
 	}
 	// RESTING. A series that ended in a brake is followed by a real pause,