Fix: null checks for quadData in ChartPanel and child components

src/charts/ModelDrawsComparison.jsx

@@ -35,9 +35,10 @@ export default function ModelDrawsComparison({ data, waves, districtName }) {
     })
   }, [data.waves])
 
-  const quadModels = data.quadData || {}
+  // Handle both cases: when quadData exists as object or is null/undefined
+  const quadModels = (data && data.quadData) ? data.quadData : {}
   // modelDraws may be null if API unavailable, handle gracefully
-  const modelDraws = data.modelDraws || null
+  const modelDraws = (data && data.modelDraws) ? data.modelDraws : null
 
   // Compute max arrests for Y-axis scaling across all quadrants and years
   const allArrestValues = []

src/charts/RateDensityRidgeline.jsx

@@ -28,7 +28,7 @@ export default function RateDensityRidgeline({ quadData, rateByGroup }) {
   }
 
   useEffect(() => {
-    if (!quadData || !selectedModel) return
+    if (!quadData || !selectedModel || !quadData[selectedModel]) return
 
     const rows = quadData[selectedModel] || []
     

src/components/ChartPanel.jsx

@@ -90,7 +90,7 @@ export default function ChartPanel({ district, state }) {
 
   // Chart 4-6 use quadData (4 models × 8 groups)
   const chart4Data = { timeSeries: mostRecent, waves: data.waveData, modelDraws: data.modelDraws }
-  const chart5Data = data.quadData   // all 4 quadrant model results
+  const chart5Data = data.quadData || {}   // all 4 quadrant model results
   const chart6Data = { rates: rateByGroup, nationalRates: nationalRates?.rates_per_1000 || {} }
 
   return (