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/components/TimerRef.jsx

@@ -19,14 +19,16 @@ function fmt(sec) {
   return h > 0 ? `${pad(h)}:${pad(m)}:${pad(ss)}` : `${pad(m)}:${pad(ss)}`;
 }
 
-export default function TimerRef({ values, onClose }) {
+export default function TimerRef({ values, onClose, minimums = { on: false, ft: 500 }, onMinimums }) {
   const [dir, setDir] = useState('up');      // 'up' | 'dn'
   const [running, setRunning] = useState(false);
   const [elapsed, setElapsed] = useState(0); // seconds
   const [target, setTarget] = useState(300); // count-down start (s)
   const [vbugs, setVbugs] = useState({});    // key -> bool (shown on tape, future)
-  const [minsOn, setMinsOn] = useState(false);
-  const [mins, setMins] = useState(500);     // baro minimums (ft)
+  // Minimums are lifted to App so the PFD altimeter can show the BARO MIN bug.
+  const minsOn = minimums.on, mins = minimums.ft;
+  const setMins = (fn) => onMinimums && onMinimums((m) => ({ ...m, ft: Math.max(0, typeof fn === 'function' ? fn(m.ft) : fn) }));
+  const setMinsOn = (fn) => onMinimums && onMinimums((m) => ({ ...m, on: typeof fn === 'function' ? fn(m.on) : fn }));
   const tickRef = useRef(null);
 
   useEffect(() => {