fix: real VU meter levels from pipeline instead of random animation

- Added input_level and output_level to /api/state (scaled 0-100)
- React RigScreen now reads real levels from state instead of random walk
- When no audio flows, VU meters show flat (0) instead of fake animation

frontend-react/src/App.jsx

@@ -460,23 +460,11 @@ function SlidePanel({ children, onClose }) {
 // 1. RIG SCREEN ────────────────────────────────────────────────
 function RigScreen({ state, connected }) {
   const [volume, setVolume] = useState(state?.master_volume != null ? Math.round(state.master_volume * 100) : 80);
-  const [vuL, setVuL] = useState(45);
-  const [vuR, setVuR] = useState(42);
-  const [saving, setSaving] = useState(false);
 
   useEffect(() => {
     if (state?.master_volume != null) setVolume(Math.round(state.master_volume * 100));
   }, [state?.master_volume]);
 
-  // Animated VU
-  useEffect(() => {
-    const id = setInterval(() => {
-      setVuL(prev => Math.max(10, Math.min(95, prev + (Math.random() - 0.48) * 12)));
-      setVuR(prev => Math.max(10, Math.min(95, prev + (Math.random() - 0.48) * 12)));
-    }, 90);
-    return () => clearInterval(id);
-  }, []);
-
   const handleVolume = async (val) => {
     setVolume(val);
     try {
@@ -497,6 +485,10 @@ function RigScreen({ state, connected }) {
     } catch (e) { /* ignore */ }
   };
 
+  // Real audio levels from the pipeline (0-100 scale, updated every poll cycle)
+  const inputLevel = state?.input_level ?? 0;
+  const outputLevel = state?.output_level ?? 0;
+
   return (
     <div style={{ display: "flex", flexDirection: "column", height: "100%" }}>
       <div className="screen-header">
@@ -518,8 +510,8 @@ function RigScreen({ state, connected }) {
           </div>
         </div>
         <div style={{ display: "flex", gap: 6, alignItems: "center" }}>
-          <VUMeter level={vuL} height={44} />
-          <VUMeter level={vuR} height={44} />
+          <VUMeter level={inputLevel} height={44} />
+          <VUMeter level={outputLevel} height={44} />
         </div>
       </div>
       <div className="screen-body">