fix(tci): TUNE can be switched off again, and the meters watch it

Two faults with one cause: this radio does not echo 'tune:0,true'.

So the panel never knew a tune was running. The button stayed on TUNE and
every further press sent another START — there was no way to stop it from
here at all. The state is recorded when the command is sent now; whatever
the radio says afterwards still wins, it simply never says anything.

And the transmit meters were asked for only while t.tx, which a tune
carrier does not set: the radio reports tuning as its own state, not as a
transmission. So power and SWR sat at zero for the whole tune — the exact
carrier an operator holds a tune for in order to watch an SWR on. They now
follow PTT or TUNE, and the S-meter reads '—' under our own carrier
either way.

internal/cat/tci.go

@@ -309,7 +309,11 @@ func (t *TCI) ReadState() (RigState, error) {
 	// anything while it is keyed. Fired and forgotten from here — the answers
 	// arrive on the reader like everything else — and only while transmitting,
 	// so a receiving station pays nothing for a meter nobody is watching.
-	if t.tx {
+	// Keyed by PTT **or** by TUNE. A tune carrier is exactly when the meters
+	// matter most — it is the carrier an operator is watching an SWR on — and
+	// asking only on t.tx left them at zero for the whole tune, because the
+	// radio reports tuning as its own state and not as a transmission.
+	if t.tx || t.panel.st.Tuning {
 		tx := t
 		go func() {
 			_ = tx.send("tx_power;")