feat: Yaesu control panel (meters, bands, DSP, TX), and drop a stale Flex hint

A console pane for the native Yaesu backend, in the same shape as the Icom and
Flex ones: S/PO/SWR meters, band and mode rows, AF/RF/squelch, AGC, the IPO/AMP1/
AMP2 front-end selector, ATT, NB, DNR + level, narrow filter, power in watts, mic
gain, VOX, split and ATU tune.

Three decisions worth keeping:

Panel reads are STAGGERED and live in their own file, away from ReadState. Meters
poll every cycle; settings only change when someone turns a knob, so they refresh
every 8th cycle and right after any set. Polling all of it every cycle would put
twenty queries a second on the serial link the frequency display shares.

Band buttons use the rig's own band memory (BS) rather than a frequency we pick,
so 20 m lands where the operator last was on 20 m — what the radio's own band
keys do.

A set is followed by a read-back, so the panel shows what the RIG ended up with,
not what we asked for; the two differ whenever a value is out of range or the
mode forbids the control. And a control the model lacks keeps its previous value
instead of dropping to zero, which reads as a setting that reset itself.

The S9 point of the S-meter scale is a hypothesis (the manual does not state it)
and is commented as such — one number to correct if reports come out an S unit
off, rather than a fudge spread through the RST helper.

Also removes the FlexRadio settings blurb, which explained the backend to
someone who had already chosen it.

frontend/src/components/SettingsModal.tsx

@@ -156,6 +156,7 @@ interface Props {
   onMainPaneChanged?: (side: 'left' | 'right', value: string) => void; // live Main-view layout update
   flexAvailable?: boolean; // CAT backend is FlexRadio → offer it as a Main pane
   icomAvailable?: boolean; // CAT backend is Icom → offer the Icom console as a Main pane
+  yaesuAvailable?: boolean; // CAT backend is Yaesu → offer the Yaesu console as a Main pane
 }
 
 // Pretty little card showing what OpsLog will stamp on each QSO based on
@@ -817,7 +818,7 @@ function RelayAutoPanel() {
 // cluster grid or the worked-before grid. Per-profile (stored via SetUIPref,
 // which is profile-prefixed). Self-contained so it owns its async-loaded state.
 const MAIN_PANE_VALUES = ['map1', 'map2', 'cluster', 'worked', 'recent', 'netcontrol'];
-function MainViewPanes({ onChanged, flexAvailable, icomAvailable }: { onChanged?: (side: 'left' | 'right', value: string) => void; flexAvailable?: boolean; icomAvailable?: boolean }) {
+function MainViewPanes({ onChanged, flexAvailable, icomAvailable, yaesuAvailable }: { onChanged?: (side: 'left' | 'right', value: string) => void; flexAvailable?: boolean; icomAvailable?: boolean; yaesuAvailable?: boolean }) {
   const { t } = useI18n();
   const [left, setLeft] = useState('map1');
   const [right, setRight] = useState('map2');
@@ -826,10 +827,11 @@ function MainViewPanes({ onChanged, flexAvailable, icomAvailable }: { onChanged?
     ...MAIN_PANE_VALUES,
     ...(flexAvailable ? ['flex'] : []),
     ...(icomAvailable ? ['icom'] : []),
+    ...(yaesuAvailable ? ['yaesu'] : []),
   ].map((value) => ({ value, label: t(`settings.pane.${value}`) }))
     .sort((a, b) => a.label.localeCompare(b.label));
   useEffect(() => {
-    const valid = (v: string) => v === 'flex' || v === 'icom' || MAIN_PANE_VALUES.includes(v);
+    const valid = (v: string) => v === 'flex' || v === 'icom' || v === 'yaesu' || MAIN_PANE_VALUES.includes(v);
     Promise.all([GetUIPref('mainPaneLeft').catch(() => ''), GetUIPref('mainPaneRight').catch(() => '')])
       .then(([l, r]) => { if (valid(l)) setLeft(l); if (valid(r)) setRight(r); });
   }, []);
@@ -1024,7 +1026,7 @@ const ICOM_MODELS: { name: string; addr: number }[] = [
   { name: 'IC-9700', addr: 0xA2 },
 ];
 
-export function SettingsModal({ onClose, onSaved, initialSection, onMainPaneChanged, flexAvailable, icomAvailable }: Props) {
+export function SettingsModal({ onClose, onSaved, initialSection, onMainPaneChanged, flexAvailable, icomAvailable, yaesuAvailable }: Props) {
   const { t } = useI18n();
   const [selected, setSelected] = useState<SectionId>((initialSection as SectionId) || 'station');
   const [loading, setLoading] = useState(true);
@@ -2664,11 +2666,6 @@ export function SettingsModal({ onClose, onSaved, initialSection, onMainPaneChan
           </p>
           </>
           )}
-          {catCfg.backend === 'flex' && (
-            <p className="text-xs text-muted-foreground">
-              {t('cat.flexHint')}
-            </p>
-          )}
         </div>
       </>
     );
@@ -5133,7 +5130,7 @@ export function SettingsModal({ onClose, onSaved, initialSection, onMainPaneChan
           </label>
           <TelemetryToggle />
 
-          <MainViewPanes onChanged={onMainPaneChanged} flexAvailable={flexAvailable} icomAvailable={icomAvailable} />
+          <MainViewPanes onChanged={onMainPaneChanged} flexAvailable={flexAvailable} icomAvailable={icomAvailable} yaesuAvailable={yaesuAvailable} />
 
           <div className="border-t border-border/60 pt-4 space-y-2">
             <h4 className="text-sm font-semibold text-foreground">{t('gen.pwEnc')}</h4>