feat: SPE Expert amplifier control (serial/TCP) — OPERATE toggle + live status

Implements the SPE Application Programmer's Guide protocol: packets
0x55 0x55 0x55|CNT|DATA|CHK (sum%256), OPERATE key 0x0D (toggles STANDBY/OPERATE)
and STATUS request 0x90 whose 0xAA-framed reply is a 19-field CSV (mode, RX/TX,
band, power level, output W, SWR, V/I, temp, warnings, alarms). internal/spe
polls status ~1/s over USB serial (go.bug.st/serial, 8N1) or TCP (RS232-to-
Ethernet bridge) — same codec, different transport.

Wired via startPGXL (starts the SPE client for spe* types), bindings GetSPEStatus
/ SPESetOperate, and a live status card + OPERATE/STANDBY toggle in the Amplifier
settings panel. Only the two example-anchored commands are sent (safe); other
keystroke codes were ambiguous in the guide's table. Untested on hardware.

frontend/src/components/SettingsModal.tsx

@@ -13,7 +13,7 @@ import {
   GetRotatorSettings, SaveRotatorSettings, TestRotator, RotatorPark, RotatorStop,
   GetUltrabeamSettings, SaveUltrabeamSettings, TestUltrabeam,
   GetAntGeniusSettings, SaveAntGeniusSettings,
-  GetPGXLSettings, SavePGXLSettings,
+  GetPGXLSettings, SavePGXLSettings, GetSPEStatus, SPESetOperate,
   GetWinkeyerSettings, SaveWinkeyerSettings, ListSerialPorts,
   GetAudioSettings, SaveAudioSettings, ListAudioInputDevices, ListAudioOutputDevices, PickAudioFolder, TestPTT,
   GetClublogCtyInfo, SetClublogCtyEnabled, DownloadClublogCty,
@@ -648,6 +648,49 @@ type RelayRuleUI = { device_id: string; relay: number; mode: string; freq_lo_khz
 type StationDevUI = { id: string; type: string; name: string; labels: string[] };
 const RELAY_BANDS = ['160m', '80m', '60m', '40m', '30m', '20m', '17m', '15m', '12m', '10m', '6m', '4m', '2m', '70cm'];
 const relayCountUI = (type: string) => (type === 'kmtronic' || type === 'denkovi' ? 8 : 5);
+
+// Live SPE Expert amplifier status + OPERATE/STANDBY toggle. Module-scoped (not a
+// nested component) so it isn't remounted on every parent render. Polls once a
+// second while shown.
+function SPEStatusCard() {
+  const [st, setSt] = useState<any>({ connected: false });
+  useEffect(() => {
+    let alive = true;
+    const tick = () => GetSPEStatus().then((s) => alive && setSt(s || {})).catch(() => {});
+    tick();
+    const id = window.setInterval(tick, 1000);
+    return () => { alive = false; window.clearInterval(id); };
+  }, []);
+  const operate = !!st.operate;
+  return (
+    <div className="rounded-md border border-border p-3 space-y-2 text-xs max-w-xl">
+      <div className="flex items-center gap-2">
+        <span className={cn('size-2 rounded-full', st.connected ? 'bg-success animate-pulse' : 'bg-danger')} />
+        <span className="font-semibold">{st.connected ? `SPE ${st.model || 'Expert'}` : 'SPE — not connected'}</span>
+        {!st.connected && st.last_error && <span className="text-danger truncate text-[10px]">{st.last_error}</span>}
+        <span className="flex-1" />
+        <Button size="sm" variant={operate ? 'default' : 'outline'} disabled={!st.connected}
+          onClick={() => SPESetOperate(!operate).catch(() => {})}
+          title="Toggle OPERATE / STANDBY">
+          {operate ? 'OPERATE' : 'STANDBY'}
+        </Button>
+      </div>
+      {st.connected && (
+        <div className="grid grid-cols-4 gap-x-3 gap-y-1 font-mono text-[11px]">
+          <div>{st.tx ? 'TX' : 'RX'}</div>
+          <div>Band {st.band}</div>
+          <div>Pwr {st.power_level}</div>
+          <div>{st.output_w} W</div>
+          <div>SWR {Number(st.swr_ant ?? 0).toFixed(2)}</div>
+          <div>{st.temp_c}°C</div>
+          <div>{st.volt_pa} V</div>
+          <div>{st.curr_pa} A</div>
+          {(st.warnings || st.alarms) && <div className="col-span-4 text-warning">⚠ {st.warnings} {st.alarms}</div>}
+        </div>
+      )}
+    </div>
+  );
+}
 function RelayAutoPanel() {
   const { t } = useI18n();
   const [enabled, setEnabled] = useState(false);
@@ -2724,9 +2767,10 @@ export function SettingsModal({ onClose, onSaved, initialSection, onMainPaneChan
             </div>
           )}
 
+          {!isPGXL && pgxl.enabled && <SPEStatusCard />}
           {!isPGXL && (
-            <p className="text-xs text-warning">
-              SPE Expert control is not wired up yet — these settings are saved, but OpsLog can't command the amp until its serial protocol is implemented.
+            <p className="text-[10px] text-muted-foreground">
+              SPE control uses the amplifier's proprietary serial protocol (OPERATE toggle + live status). Save to (re)connect. Band / power-level / antenna are still managed on the amp from the transceiver CAT.
             </p>
           )}
         </div>