G1000: manual-accurate radios, baro units, declutter, minimums, OBS, audio panel

Aligned to the official X-Plane 1000 manual:
- NAV radio: active RIGHT / standby LEFT (boxed) per S.12 (COM already correct)
- ALT UNIT softkey (IN / HPA) in the PFD submenu, baro readout converts (S.20)
- DCLTR cycles 3 levels (land / +NDB / flight-plan only) with DCLTR-n label (S.56)
- TOPO and TERRAIN are now independent toggles (relief vs awareness overlay) (S.57)
- Barometric MINIMUMS: BARO MIN bug + readout on the altimeter, amber "MINIMUMS"
  annunciation at/below the decision altitude; set via TMR/REF (lifted to App)
- OBS mode: HSI course follows the CRS knob (magenta "OBS"), sequencing suspended
- New Audio Panel tab (COM mic/receive, MKR/DME/ADF, intercom, Display Backup) (S.91)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

web/src/App.jsx

@@ -10,6 +10,7 @@ import Bezel from './components/Bezel.jsx';
 import DirectTo from './components/DirectTo.jsx';
 import Proc from './components/Proc.jsx';
 import FplPage from './components/FplPage.jsx';
+import AudioPanel from './components/AudioPanel.jsx';
 
 // Compact line icons for the nav rail (stroke = currentColor).
 const ICONS = {
@@ -19,6 +20,7 @@ const ICONS = {
   fms: 'M4 6h14M4 11h14M4 16h9',
   ap: 'M11 4a7 7 0 100 14 7 7 0 000-14zM11 4v3M11 15v3M4 11h3M15 11h3',
   vfr: 'M11 4a7 7 0 100 14 7 7 0 000-14zM11 11l4.5-3',
+  audio: 'M11 4a6 6 0 00-6 6v5M17 15v-5a6 6 0 00-6-6M4 14h2.5v4.5H4zM15.5 14H18v4.5h-2.5z',
 };
 function Icon({ name }) {
   return (
@@ -37,6 +39,7 @@ const TABS = [
   { id: 'fms', label: 'FMS' },
   { id: 'vfr', label: 'VFR' },
   { id: 'ap', label: 'Autopilot' },
+  { id: 'audio', label: 'Audio' },
 ];
 
 export default function App() {
@@ -65,8 +68,14 @@ export default function App() {
   const toggleWin = (id) => setWin((w) => (w === id ? null : id));
   const nrst = win === 'nrst', tmr = win === 'tmr', dme = win === 'dme', alerts = win === 'alerts';
   const fpl = win === 'fpl', dto = win === 'dto', proc = win === 'proc';
-  // MFD map mode (base layer), switched via the Map-Opt softkeys.
+  // MFD map mode (base layer + overlays), switched via the Map-Opt softkeys.
   const [mapMode, setMapMode] = useState({ base: 'topo' });
+  // Altimeter barometric units (false = inHg, true = hectopascal) — PFD ALT UNIT softkey.
+  const [baroHpa, setBaroHpa] = useState(false);
+  // Barometric minimums (set in TMR/REF) — shown on the PFD altimeter as BARO MIN.
+  const [minimums, setMinimums] = useState({ on: false, ft: 500 });
+  // OBS (omni-bearing select) mode — suspends GPS sequencing, course set by CRS knob.
+  const [obs, setObs] = useState(false);
   // MFD page group (MAP / FPL / NRST) — selected by the FMS knob, like the real G1000.
   const MFD_PAGES = ['map', 'fpl', 'nrst'];
   const [mfdPage, setMfdPage] = useState('map');
@@ -129,15 +138,17 @@ export default function App() {
             inset={inset} onSetInset={setInset} insetMode={insetMode} onInsetMode={setInsetMode}
             nrst={nrst} onToggleNrst={() => toggleWin('nrst')} onDirect={() => toggleWin('dto')}
             tmr={tmr} onToggleTmr={() => toggleWin('tmr')} dme={dme} onToggleDme={() => toggleWin('dme')}
-            alerts={alerts} onToggleAlerts={() => toggleWin('alerts')} onProc={() => toggleWin('proc')} onFpl={() => toggleWin('fpl')}>
-            <PFD values={xp.values} command={xp.command} svt={svt3d} inset={inset} insetMode={insetMode} nrst={nrst} onCloseNrst={() => setWin(null)}
+            alerts={alerts} onToggleAlerts={() => toggleWin('alerts')} onProc={() => toggleWin('proc')} onFpl={() => toggleWin('fpl')} onClr={() => setWin(null)}
+            altHpa={baroHpa} onAltUnit={setBaroHpa} obs={obs} onObs={() => setObs((v) => !v)}>
+            <PFD values={xp.values} command={xp.command} connected={xp.xpConnected} svt={svt3d} inset={inset} insetMode={insetMode} nrst={nrst} onCloseNrst={() => setWin(null)}
               tmr={tmr} onCloseTmr={() => setWin(null)} dme={dme} onCloseDme={() => setWin(null)}
-              alerts={alerts} onCloseAlerts={() => setWin(null)} flightPlan={xp.flightPlan} fp={xp.fp} />
+              alerts={alerts} onCloseAlerts={() => setWin(null)} baroHpa={baroHpa} obs={obs}
+              minimums={minimums} onMinimums={setMinimums} flightPlan={xp.flightPlan} fp={xp.fp} />
             {dialogs}
           </Bezel>
         )}
         {tab === 'mfd' && (
-          <Bezel variant="mfd" xp={xp} knobMode={knobMode} mapMode={mapMode} onMapMode={setMapMode} onDirect={() => toggleWin('dto')} onProc={() => toggleWin('proc')} onFms={cycleMfd} onFpl={() => setMfdPage('fpl')}>
+          <Bezel variant="mfd" xp={xp} knobMode={knobMode} mapMode={mapMode} onMapMode={setMapMode} onDirect={() => toggleWin('dto')} onProc={() => toggleWin('proc')} onFms={cycleMfd} onFpl={() => setMfdPage('fpl')} onClr={() => setWin(null)}>
             <MFD values={xp.values} flightPlan={xp.flightPlan} fp={xp.fp} mapMode={mapMode} page={mfdPage} onCycle={cycleMfd} xp={xp} />
             {dialogs}
           </Bezel>
@@ -146,6 +157,7 @@ export default function App() {
         {tab === 'fms' && <CDU xp={xp} />}
         {tab === 'vfr' && <VFR xp={xp} />}
         {tab === 'ap' && <AutopilotPanel xp={xp} />}
+        {tab === 'audio' && <AudioPanel xp={xp} />}
       </main>
       {settings && (
         <div className="dlg-backdrop" onClick={() => setSettings(false)}>