feat(sat): Doppler tracking on the radio

The hard part of satellite tuning is not the arithmetic, it is deciding
who owns the dial. A tracker that forces both frequencies fights the
operator every time they turn the knob to follow a station across a
linear transponder; one that never touches the receiver leaves them
chasing a signal that slides nine kilohertz across a 70 cm pass.

So the operator owns the receiver and the tracker follows them. Every
second it asks the radio where the receiver actually is. Where it put it,
nothing has changed. Further than a dial-turn's tolerance, and the
operator has chosen a station: what they landed on is converted back into
a nominal frequency, and the transmitter is derived from that. Which is
the division of labour on a linear bird — the operator listens, the radio
does the sums.

Three ways to reach the radio, because a satellite pair is a shape of
operating rather than a manufacturer's feature. An IC-9700 or IC-9100 is
asked for its OWN satellite mode: it pairs main and sub, gives full
duplex, and keeps the dials linked the way its designers meant, which is
always better than an imitation built out of split. A Flex gets two
slices, A the downlink and B the uplink, created when missing, because
"slice B does not exist" is not something to make an operator fix at the
start of a ten-minute pass. Everything else gets the downlink, and is
told so — half the job announced beats half the job hidden.

What goes in the log is the NOMINAL pair. Two stations working each other
through a transponder read different numbers off their dials at the same
instant; the only figure they can both agree on is the transponder's own.
FREQ is the uplink and FREQ_RX the downlink — the one place a satellite
QSO differs from every other kind, and the reason FREQ alone cannot
describe one.

profilereload_test.go

@@ -34,6 +34,12 @@ func TestProfileSwitchReappliesEveryStartupDevice(t *testing.T) {
 		// sweepers. Its settings do follow the profile: reloadAfterProfileSwitch
 		// calls applyAutoCall, which re-reads them and clears the target.
 		"startAutoCall": "a single sweeper goroutine; applyAutoCall in the reload carries the settings",
+		// The elements and the frequency plan are FILES, shared by every
+		// profile — there is one sky. What is per profile (the favourites, the
+		// minimum elevation, the locator) is read live on every call, so a
+		// switch is already reflected without rebuilding anything. The tracker,
+		// which does transmit, IS stopped by reloadAfterProfileSwitch.
+		"startSatellites": "one sky: the elements and the plan are shared files, and the per-profile settings are read live",
 	}
 
 	startup := body(t, string(src), "func (a *App) startup(ctx context.Context) {")