correct the error

.gitignore

@@ -72,4 +72,6 @@ tests/**
 # Root-anchored: backend/candidate_forms/ is the forms domain package and IS tracked.
 /candidate_forms/
 frontend/dist/** */
-docker.local.frontend/dist/** */
+docker.local.frontend/dist/** */
+frontend/dist/index.html
+frontend/dist/index.html

frontend/src/lib/charts.js

@@ -48,7 +48,17 @@ function css(name) { return getComputedStyle(document.documentElement).getProper
     const dpr = window.devicePixelRatio || 1;
     const rect = canvas.getBoundingClientRect();
     const w = rect.width || canvas.clientWidth || 600;
-    const h = parseInt(canvas.getAttribute('height')) || 260;
+    // The LOGICAL height, remembered on first setup. Reading the `height`
+    // attribute here instead would read back the DEVICE-pixel value written
+    // below (h * dpr): with dpr > 1 every redraw multiplied the canvas by dpr,
+    // and the ResizeObserver on the auto-height .chart-wrap fed each growth
+    // straight back in — canvases reached millions of px tall and the chart
+    // became an invisible speck at the top of a giant blank canvas.
+    let h = Number(canvas.dataset.baseHeight);
+    if (!h) {
+      h = parseInt(canvas.getAttribute('height')) || 260;
+      canvas.dataset.baseHeight = String(h);
+    }
     canvas.width = w * dpr; canvas.height = h * dpr;
     canvas.style.height = h + 'px';
     const ctx = canvas.getContext('2d');

frontend/src/ui/Chart.jsx

@@ -29,6 +29,11 @@ export default function Chart({ type, data, options, height = 260, className = '
     const canvas = ref.current
     if (!canvas || typeof Charts[type] !== 'function') return undefined
 
+    // setup() caches the logical height on first draw (dataset.baseHeight) so a
+    // redraw never reads back the device-pixel height it wrote. Clear it here so
+    // a changed `height` prop is picked up rather than the stale cached value.
+    delete canvas.dataset.baseHeight
+
     const draw = () => {
       if (canvas.isConnected && canvas.getBoundingClientRect().width > 0) {
         Charts[type](canvas, data, options)