feat(lotw): name the station callsign on each downloaded confirmation

With 'All my callsigns' the report spans F4BPO, F4BPO/P and TM2Q at once, and a
list mixing them says nothing about which one a confirmation belongs to — which
is the question that option creates.

The column appears only when the rows actually carry a station: the other
services return one, and an empty column for them would be noise.

app.go

@@ -11576,14 +11576,18 @@ func (a *App) runManualUpload(svc extsvc.Service, ids []int64, cfg extsvc.Extern
 // with award-style NEW flags computed against the log's prior confirmations.
 type ConfirmationItem struct {
 	Callsign string `json:"callsign"`
-	QSODate  string `json:"qso_date"` // ISO UTC
-	Band     string `json:"band"`
-	Mode     string `json:"mode"`
-	Country  string `json:"country"`
-	NewDXCC  bool   `json:"new_dxcc"`
-	NewBand  bool   `json:"new_band"`
-	NewMode  bool   `json:"new_mode"` // new mode CLASS (Phone/CW/Digital) for the entity
-	NewSlot  bool   `json:"new_slot"`
+	// Station is the callsign the QSO was made UNDER, which the download can now
+	// span ("All my callsigns"): a list mixing F4BPO, F4BPO/P and TM2Q says
+	// nothing useful unless each line says which of them it belongs to.
+	Station string `json:"station"`
+	QSODate string `json:"qso_date"` // ISO UTC
+	Band    string `json:"band"`
+	Mode    string `json:"mode"`
+	Country string `json:"country"`
+	NewDXCC bool   `json:"new_dxcc"`
+	NewBand bool   `json:"new_band"`
+	NewMode bool   `json:"new_mode"` // new mode CLASS (Phone/CW/Digital) for the entity
+	NewSlot bool   `json:"new_slot"`
 }
 
 // GetSlotStats returns the worked/confirmed slot + DXCC tallies for the QSL
@@ -12365,6 +12369,7 @@ func (a *App) runDownloadConfirmations(ctx context.Context, svc extsvc.Service,
 			}
 			it := ConfirmationItem{
 				Callsign: q.Callsign,
+				Station:  strings.ToUpper(strings.TrimSpace(rec["station_callsign"])),
 				QSODate:  q.QSODate.UTC().Format(time.RFC3339),
 				Band:     q.Band,
 				Mode:     q.Mode,