feat: Tuner Genius XL — A/B channels, plus FlexRadio panel + Station Control cards

Push the tuner control further so it mirrors the native 4O3A app and the way the
PowerGenius XL is surfaced.

Backend (internal/tunergenius):
- Status now carries both RF channels A and B (source/mode, band, frequency,
  bound Flex nickname, per-channel bypass, antenna, PTT), the active channel,
  the C1/L/C2 relay-network positions, and the 3-way-vs-SO2R hardware variant
  (learned once from the `info` reply). Flat freq/antenna still mirror the active
  channel for the compact widget.
- New TunerGeniusActivate(ch) binding → `activate ch=N` (or `ant=N` on 3-way).

Frontend:
- New shared TunerCard, styled exactly like AmpCard (PWR/SWR meter bars,
  A/B channel selector with source+freq+antenna, Tune/Bypass/Operate). Used in
  BOTH the FlexRadio panel (its own card, like the PGXL) and Station Control.
- Docked TunerGeniusPanel widget now shows the two channels A/B with their
  source/frequency/antenna and lets you click to make one active — the missing
  A/B state the user flagged.
- i18n EN/FR for the new labels (channels, antenna, in-line/bypassed, title).

Still UNTESTED on hardware — verify the per-channel field names/units and the
activate behaviour on the real box.

frontend/src/components/FlexPanel.tsx

@@ -5,6 +5,7 @@ import {
   FlexSetProcessor, FlexSetProcessorLevel, FlexSetMon, FlexSetMonLevel, FlexSetMic,
   FlexMox, FlexAmpOperate,
   GetPGXLStatus, PGXLSetFanMode,
+  GetTunerGeniusStatus, GetTunerGeniusSettings,
   GetAmpStatuses, AmpOperate, AmpPower, AmpPowerLevel,
   FlexSetAGCMode, FlexSetAGCThreshold, FlexSetAudioLevel, FlexSetMute, FlexSetRXAntenna, FlexSetTXAntenna, FlexSetSplit, FlexSetActiveSlice, FlexSetTXSlice,
   FlexSetRIT, FlexSetRITFreq, FlexSetXIT, FlexSetXITFreq,
@@ -19,6 +20,8 @@ import { EventsOn } from '../../wailsjs/runtime/runtime';
 import { cn } from '@/lib/utils';
 import { useI18n } from '@/lib/i18n';
 import { sMeterRST } from '@/lib/rst';
+import { TunerCard } from '@/components/TunerCard';
+import type { TGStatus } from '@/components/TunerGeniusPanel';
 
 type FlexState = {
   available: boolean; model?: string;
@@ -354,6 +357,20 @@ export function FlexPanel({ onCWSpeed, onReportRST }: { onCWSpeed?: (wpm: number
     return () => { alive = false; window.clearInterval(id); };
   }, []);
 
+  // Tuner Genius XL direct connection — its own card in the Flex panel (like PGXL).
+  const [tg, setTg] = useState<TGStatus>({ connected: false });
+  const [tgEnabled, setTgEnabled] = useState(false);
+  useEffect(() => {
+    let alive = true;
+    const tick = async () => {
+      try { const en: any = await GetTunerGeniusSettings(); if (alive) setTgEnabled(!!en?.enabled); } catch {}
+      try { const s: any = await GetTunerGeniusStatus(); if (alive && s) setTg(s as TGStatus); } catch {}
+    };
+    tick();
+    const id = window.setInterval(tick, 1500);
+    return () => { alive = false; window.clearInterval(id); };
+  }, []);
+
   // Configured amplifiers (Settings → Amplifier) — possibly SEVERAL (some ops
   // run two SPEs in parallel). The card shows ONE at a time; the dropdown picks
   // which, and the choice is remembered per panel.
@@ -1084,6 +1101,10 @@ export function FlexPanel({ onCWSpeed, onReportRST }: { onCWSpeed?: (wpm: number
           </Card>
         )}
 
+        {/* Tuner Genius XL — 4O3A ATU, its own card when enabled (Settings →
+            Tuner Genius). Same card shown in Station Control. */}
+        {tgEnabled && <TunerCard status={tg} t={t} />}
+
       </div>
     </div>
   );