fix: detect only upward peaks (zScore > 5), min 15min zoom padding

- Changed Math.abs(zScore) > threshold to zScore > threshold
  so only upward spikes are detected (not dips below average)
- Zoom padding minimum 15 minutes on each side for short peak intervals

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/components/charts/NetworkChart.tsx

@@ -31,7 +31,8 @@ export default forwardRef<NetworkChartHandle, NetworkChartProps>(function Networ
       const maxTime = Math.max(...allTimes);
       const range = maxTime - minTime;
       if (range === 0) return;
-      const padding = (endMs - startMs) * 0.5;
+      const MIN_PADDING = 15 * 60 * 1000; // 15분
+      const padding = Math.max(MIN_PADDING, (endMs - startMs) * 0.5);
       const s = Math.max(0, ((startMs - padding - minTime) / range) * 100);
       const e = Math.min(100, ((endMs + padding - minTime) / range) * 100);
       chart.dispatchAction({ type: 'dataZoom', start: s, end: e });

src/components/charts/TimeSeriesChart.tsx

@@ -37,7 +37,8 @@ export default forwardRef<ChartHandle, TimeSeriesChartProps>(function TimeSeries
       const maxTime = Math.max(...allTimes);
       const range = maxTime - minTime;
       if (range === 0) return;
-      const padding = (endMs - startMs) * 0.5;
+      const MIN_PADDING = 15 * 60 * 1000; // 15분
+      const padding = Math.max(MIN_PADDING, (endMs - startMs) * 0.5);
       const s = Math.max(0, ((startMs - padding - minTime) / range) * 100);
       const e = Math.min(100, ((endMs + padding - minTime) / range) * 100);
       chart.dispatchAction({ type: 'dataZoom', start: s, end: e });

src/lib/analytics.ts

@@ -43,7 +43,7 @@ export function detectPeaks(
 
   const points = dataPoints.map((d) => {
     const zScore = stddev === 0 ? 0 : (d.value - mean) / stddev;
-    return { ...d, zScore, isPeak: Math.abs(zScore) > threshold };
+    return { ...d, zScore, isPeak: zScore > threshold };
   });
 
   const peaks: PeakInfo[] = [];