feat(hamqth): QSO upload to the HamQTH logbook — the 8th external service

qso_realtime.php with the account's callbook credentials (which the
external-services config falls back to when its own are blank), one ADIF
record per QSO, prg=OpsLog. HTTP status IS the answer: 200 saved, 400
rejected (a duplicate counts as delivered, like HRDLog's insert 0), 403
credentials. Sent-state lives in APP_OPSLOG_HAMQTH_SENT extras like
HAMLOG.online — ADIF names no HamQTH field. Auto-upload on log, on-close
batch, right-click Send to, QSL Manager backlog, and a Test button that
authenticates against the callbook login, which cannot touch the log.

Fixes a real mis-route on the way: manual 'Send to HAMLOG.online' had no
branch in runManualUpload and fell through to QRZ.com — the selection was
uploaded to the wrong service with the QRZ key. Both extras-stamped
services now have their own branch.

app_secret.go

@@ -25,6 +25,7 @@ var sensitiveSettingKeys = map[string]bool{
 	keyExtLoTWKeyPassword: true,
 	keyExtLoTWWebPassword: true,
 	keyExtHRDLogCode:      true,
+	keyExtHamqthPassword:  true,
 	keyExtEQSLPassword:    true,
 	keyExtCloudlogAPIKey:  true,
 	// The web-publish config is one JSON blob and the FTP password lives inside