feat(visualizer): add build overlay toggle

Default is off so candles match production; enable via the new Build button when needed.

apps/visualizer/src/features/chart/TradingChart.tsx

@@ -25,6 +25,7 @@ type Props = {
   ema20?: SeriesPoint[];
   bb20?: { upper: SeriesPoint[]; lower: SeriesPoint[]; mid: SeriesPoint[] };
   showIndicators: boolean;
+  showBuild: boolean;
   bucketSeconds: number;
   seriesKey: string;
   fib?: FibRetracement | null;
@@ -116,6 +117,7 @@ export default function TradingChart({
   ema20,
   bb20,
   showIndicators,
+  showBuild,
   bucketSeconds,
   seriesKey,
   fib,
@@ -596,12 +598,29 @@ export default function TradingChart({
     s.bbLower?.setData(bbLower);
     s.bbMid?.setData(bbMid);
 
+    s.build.applyOptions({ visible: showBuild });
+    if (!showBuild) {
+      buildSamplesRef.current.clear();
+      buildKeyRef.current = seriesKey;
+      lastBuildCandleStartRef.current = null;
+      s.build.setData([]);
+    }
+
     if (buildKeyRef.current !== seriesKey) {
       buildSamplesRef.current.clear();
       buildKeyRef.current = seriesKey;
       lastBuildCandleStartRef.current = null;
     }
 
+    if (!showBuild) {
+      s.sma20?.applyOptions({ visible: showIndicators });
+      s.ema20?.applyOptions({ visible: showIndicators });
+      s.bbUpper?.applyOptions({ visible: showIndicators });
+      s.bbLower?.applyOptions({ visible: showIndicators });
+      s.bbMid?.applyOptions({ visible: showIndicators });
+      return;
+    }
+
     const bs = resolveBucketSeconds(bucketSeconds, candles);
     const eps = 1e-3;
     const maxPointsPerCandle = 600;
@@ -714,7 +733,21 @@ export default function TradingChart({
     s.bbUpper?.applyOptions({ visible: showIndicators });
     s.bbLower?.applyOptions({ visible: showIndicators });
     s.bbMid?.applyOptions({ visible: showIndicators });
-  }, [candleData, volumeData, oracleData, smaData, emaData, bbUpper, bbLower, bbMid, showIndicators, candles, bucketSeconds, seriesKey]);
+  }, [
+    candleData,
+    volumeData,
+    oracleData,
+    smaData,
+    emaData,
+    bbUpper,
+    bbLower,
+    bbMid,
+    showIndicators,
+    showBuild,
+    candles,
+    bucketSeconds,
+    seriesKey,
+  ]);
 
   useEffect(() => {
     const s = seriesRef.current;