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.

frontend/src/components/TCIPanel.tsx

@@ -274,15 +274,15 @@ export function TCIPanel({ onReportRST }: { onReportRST?: (rst: string) => void
             There is no temperature: the protocol has no such command, and a
             made-up figure on a transmitter is the kind somebody trusts. */}
         <Card icon={Activity} title={t('tcip.meters')}>
-          <MeterBar label="S-METER" value={st.tx ? 0 : sBar(st.smeter)} lo={0} hi={100}
+          <MeterBar label="S-METER" value={st.tx || st.tuning ? 0 : sBar(st.smeter)} lo={0} hi={100}
             accent="#16a34a" segColor={sSegColor}
-            display={st.tx ? '—' : `${s.label}  ${st.smeter} dBm`}
+            display={st.tx || st.tuning ? '—' : `${s.label}  ${st.smeter} dBm`}
             onClick={() => {
               if (st.tx || !onReportRST) return;
               onReportRST(sMeterRST(s.s, s.over, mode));
             }}
             title={t('tcip.sMeterHint')} />
-          {st.tx && (
+          {(st.tx || st.tuning) && (
             <div className="grid grid-cols-1 sm:grid-cols-2 gap-2">
               <MeterBar label="PWR" value={st.tx_power_w} lo={0} hi={Math.max(10, Math.ceil(st.tx_power_w / 10) * 10)}
                 accent="#0ea5e9" display={`${st.tx_power_w.toFixed(1)} W`} />

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;")

internal/cat/tci_panel.go

@@ -341,7 +341,18 @@ func (t *TCI) SetLock(on bool) error { return t.send(fmt.Sprintf("lock:0,%t;", o
 //
 // It TRANSMITS, at tune_drive rather than at drive — which is the setting to
 // check before pressing it, and why the panel shows the two side by side.
-func (t *TCI) SetTune(on bool) error { return t.send(fmt.Sprintf("tune:0,%t;", on)) }
+//
+// The state is recorded HERE rather than waited for. This radio does not echo
+// "tune:0,true", so the panel had no way of knowing a tune was running: the
+// button stayed on TUNE and every further press sent another START, which is
+// why it could not be switched off again. Whatever the radio says afterwards
+// still wins — it simply never says anything.
+func (t *TCI) SetTune(on bool) error {
+	t.mu.Lock()
+	t.panel.st.Tuning = on
+	t.mu.Unlock()
+	return t.send(fmt.Sprintf("tune:0,%t;", on))
+}
 
 func clampTCIPct(v int) int {
 	if v < 0 {