fix(sat): saving the settings refreshes the Satellites tab

The tab read the followed list, the horizon and the locator once, when it
was mounted. It is normally open BEHIND the settings window while those
are edited, so un-following QO-100 left it in the pass table and in the
dropdown until the tab was reopened — indistinguishable, from the
outside, from a setting that had not saved at all.

SaveSatSettings now emits sat:settings, and the panel reloads the birds
and the passes on it, the same way it already does on sat:tle. One event
for every key: they all change what the tab should be showing. The
selection needs nothing new — a satellite that has stopped being
followed drops out of the dropdown, and the effect that keeps the
selection inside that list moves to the first one remaining.

app_sat.go

@@ -364,6 +364,15 @@ func (a *App) SaveSatSettings(s SatSettings) error {
 			return err
 		}
 	}
+	// The Satellites tab is usually open BEHIND the settings window, and it
+	// read the followed list once when it was mounted: dropping QO-100 left it
+	// in the pass table and in the dropdown until the tab was reopened, which
+	// looks exactly like a setting that did not save. Every key written here
+	// changes what the tab should show — the followed list, the horizon, the
+	// window, the locator — so one event covers them all.
+	if a.ctx != nil {
+		wruntime.EventsEmit(a.ctx, "sat:settings")
+	}
 	return nil
 }