feat: relay auto-control by frequency / band (PstRotator-style)

Automatically switches the Station Control relay boards from the rig's
current frequency / band. Each relay carries one rule: off (manual), a
frequency window (ON inside [lo,hi] kHz, OFF outside), or a set of bands
(ON on those bands, OFF elsewhere). Evaluated on every CAT frequency/band
change; a relay is only switched when its desired state actually changed,
so tuning within a range doesn't hammer the board.

A cached atomic flag keeps the CAT hot path a no-op when the feature is off
(important during FT8 slice churn). Saving re-applies from the live
frequency so a changed rule takes effect immediately.

New Settings → Hardware → Relay auto-control section: master enable plus a
per-relay mode (Off / Frequency / Band) with kHz range inputs or band
chips, per configured relay board. i18n EN + FR. Azimuth/Time modes (the
other two PstRotator tabs) are left for later.

frontend/src/components/SettingsModal.tsx

@@ -43,6 +43,7 @@ import {
   GetUIPref, SetUIPref,
   GetFlexState, GetFlexBandAntennas, SaveFlexBandAntennas,
   GetADIFMonitor, SaveADIFMonitor, PickADIFMonitorFile,
+  GetRelayAuto, SaveRelayAuto, GetStationDevices,
 } from '../../wailsjs/go/main/App';
 import type { profile as profileModels } from '../../wailsjs/go/models';
 import type { LookupSettingsForm, StationSettingsForm, ListsSettingsForm, ModePresetForm } from '@/types';
@@ -187,6 +188,7 @@ type SectionId =
   | 'antgenius'
   | 'pgxl'
   | 'flex'
+  | 'relayauto'
   | 'audio';
 
 type TreeNode =
@@ -204,6 +206,7 @@ function buildTree(flexAvailable: boolean, t: (k: string) => string): TreeNode[]
     { kind: 'item', label: t('sec.antgenius'),    id: 'antgenius' },
     { kind: 'item', label: t('sec.pgxl'),         id: 'pgxl' },
     ...(flexAvailable ? [{ kind: 'item', label: t('sec.flex'), id: 'flex' } as TreeNode] : []),
+    { kind: 'item', label: t('sec.relayauto'),    id: 'relayauto' },
     { kind: 'item', label: t('sec.audio'),        id: 'audio' },
   ];
   return [
@@ -248,6 +251,7 @@ const SECTION_KEY: Partial<Record<SectionId, string>> = {
   uscounties: 'sec.uscounties',
   awards: 'sec.awards', cat: 'sec.cat', rotator: 'sec.rotator', winkeyer: 'sec.winkeyer', antenna: 'sec.antenna',
   antgenius: 'sec.antgenius', pgxl: 'sec.pgxl', flex: 'sec.flex', audio: 'sec.audio', general: 'sec.general', email: 'sec.email',
+  relayauto: 'sec.relayauto',
 };
 
 // Map section id → friendly name (used in breadcrumb / placeholders).
@@ -274,6 +278,7 @@ const SECTION_LABELS: Partial<Record<SectionId, string>> = {
   antgenius: 'Antenna Genius',
   pgxl: 'Power Genius',
   flex: 'FlexRadio',
+  relayauto: 'Relay auto-control',
   audio: 'Audio devices',
 };
 
@@ -636,6 +641,117 @@ function ADIFMonitorPanel() {
   );
 }
 
+// RelayAutoPanel configures automatic control of the Station Control relay boards
+// from the rig's frequency / band (PstRotator-style). Each relay carries one rule:
+// off, a frequency window (kHz), or a set of bands.
+type RelayRuleUI = { device_id: string; relay: number; mode: string; freq_lo_khz: number; freq_hi_khz: number; bands: string[] };
+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' ? 8 : 5);
+function RelayAutoPanel() {
+  const { t } = useI18n();
+  const [enabled, setEnabled] = useState(false);
+  const [rules, setRules] = useState<RelayRuleUI[]>([]);
+  const [devices, setDevices] = useState<StationDevUI[]>([]);
+  const [loaded, setLoaded] = useState(false);
+  useEffect(() => {
+    Promise.all([GetRelayAuto(), GetStationDevices()])
+      .then(([cfg, devs]: any[]) => {
+        setEnabled(!!cfg?.enabled);
+        setRules((cfg?.rules ?? []) as RelayRuleUI[]);
+        setDevices((devs ?? []) as StationDevUI[]);
+      })
+      .catch(() => {})
+      .finally(() => setLoaded(true));
+  }, []);
+  const save = (en: boolean, rs: RelayRuleUI[]) => { SaveRelayAuto({ enabled: en, rules: rs } as any).catch(() => {}); };
+  const ruleFor = (dev: string, relay: number): RelayRuleUI =>
+    rules.find((r) => r.device_id === dev && r.relay === relay) ?? { device_id: dev, relay, mode: 'off', freq_lo_khz: 0, freq_hi_khz: 0, bands: [] };
+  // Apply a patch and persist (commit=true) or keep local only (commit=false, for
+  // freq inputs that persist on blur so we don't switch relays on every keystroke).
+  const patchRule = (dev: string, relay: number, patch: Partial<RelayRuleUI>, commit = true) => {
+    const next = { ...ruleFor(dev, relay), ...patch };
+    const others = rules.filter((r) => !(r.device_id === dev && r.relay === relay));
+    const all = [...others, next];
+    setRules(all);
+    if (commit) save(enabled, all);
+  };
+  const toggleBand = (dev: string, relay: number, band: string) => {
+    const cur = ruleFor(dev, relay);
+    const has = cur.bands.includes(band);
+    patchRule(dev, relay, { bands: has ? cur.bands.filter((b) => b !== band) : [...cur.bands, band] });
+  };
+
+  return (
+    <div className="space-y-4 max-w-3xl">
+      <p className="text-xs text-muted-foreground">{t('relayauto.hint')}</p>
+      <label className="flex items-center gap-2 text-sm cursor-pointer">
+        <Checkbox checked={enabled} disabled={!loaded} onCheckedChange={(c) => { const v = !!c; setEnabled(v); save(v, rules); }} />
+        {t('relayauto.enable')}
+      </label>
+
+      {devices.length === 0 && loaded && (
+        <p className="text-xs text-muted-foreground italic">{t('relayauto.noDevices')}</p>
+      )}
+
+      {devices.map((dev) => (
+        <div key={dev.id} className="rounded-md border border-border">
+          <div className="px-3 py-1.5 border-b border-border bg-muted/40 text-xs font-semibold">{dev.name || dev.id}</div>
+          <div className="divide-y divide-border/60">
+            {Array.from({ length: relayCountUI(dev.type) }, (_, i) => i + 1).map((relay) => {
+              const r = ruleFor(dev.id, relay);
+              const label = (dev.labels?.[relay - 1] || '').trim() || `${t('relayauto.relay')} ${relay}`;
+              return (
+                <div key={relay} className="flex items-start gap-3 px-3 py-2">
+                  <span className="w-28 shrink-0 text-xs font-mono pt-1.5 truncate" title={label}>{label}</span>
+                  <Select value={r.mode || 'off'} onValueChange={(v) => patchRule(dev.id, relay, { mode: v })}>
+                    <SelectTrigger className="h-8 w-32 text-xs shrink-0"><SelectValue /></SelectTrigger>
+                    <SelectContent>
+                      <SelectItem value="off">{t('relayauto.modeOff')}</SelectItem>
+                      <SelectItem value="freq">{t('relayauto.modeFreq')}</SelectItem>
+                      <SelectItem value="band">{t('relayauto.modeBand')}</SelectItem>
+                    </SelectContent>
+                  </Select>
+                  <div className="flex-1 min-w-0 pt-0.5">
+                    {r.mode === 'freq' && (
+                      <div className="flex items-center gap-1.5 text-xs">
+                        <Input type="number" className="h-8 w-24 text-xs" placeholder={t('relayauto.from')}
+                          defaultValue={r.freq_lo_khz || ''}
+                          onChange={(e) => patchRule(dev.id, relay, { freq_lo_khz: parseFloat(e.target.value) || 0 }, false)}
+                          onBlur={() => save(enabled, rules)} />
+                        <span className="text-muted-foreground">–</span>
+                        <Input type="number" className="h-8 w-24 text-xs" placeholder={t('relayauto.to')}
+                          defaultValue={r.freq_hi_khz || ''}
+                          onChange={(e) => patchRule(dev.id, relay, { freq_hi_khz: parseFloat(e.target.value) || 0 }, false)}
+                          onBlur={() => save(enabled, rules)} />
+                        <span className="text-muted-foreground">kHz</span>
+                      </div>
+                    )}
+                    {r.mode === 'band' && (
+                      <div className="flex flex-wrap gap-1">
+                        {RELAY_BANDS.map((b) => {
+                          const on = r.bands.includes(b);
+                          return (
+                            <button key={b} type="button" onClick={() => toggleBand(dev.id, relay, b)}
+                              className={cn('px-1.5 py-0.5 rounded text-[11px] font-mono border transition-colors',
+                                on ? 'bg-primary text-primary-foreground border-primary' : 'border-border text-muted-foreground hover:bg-muted')}>
+                              {b}
+                            </button>
+                          );
+                        })}
+                      </div>
+                    )}
+                  </div>
+                </div>
+              );
+            })}
+          </div>
+        </div>
+      ))}
+    </div>
+  );
+}
+
 // MainViewPanes lets the operator choose what the Main tab's left and right
 // panes show, independently: the great-circle map, the locator street map, the
 // cluster grid or the worked-before grid. Per-profile (stored via SetUIPref,
@@ -4515,6 +4631,7 @@ export function SettingsModal({ onClose, onSaved, initialSection, onMainPaneChan
     // — useState/useEffect/useI18n — get a proper component context; PANELS[x]()
     // is a plain call and hook-holding panels must go through JSX like this.
     adifmon:        () => <ADIFMonitorPanel />,
+    relayauto:      () => <RelayAutoPanel />,
     backup:         BackupPanel,
     database:       DatabasePanel,
     uscounties:     USCountiesPanel,