Fix static asset paths for /crdc-demo subdirectory deployment

- App.jsx: Use import.meta.env.BASE_URL prefix for civilytics-logo.svg (was hardcoded as '/civilytics-logo.svg' → 404 on pages.civilytics.org/crdc-demo/)
- ChartPanel.jsx: Same fix for /data/national_rates.json path — was causing JSON.parse errors because the 404 HTML response couldn't be parsed

src/App.jsx

@@ -47,7 +47,7 @@ export default function App() {
       <header className="cv-header cv-wrap">
         <a href="/crdc-demo" aria-label="Civilytics" style={{ display: 'block' }}>
           <img
-            src="/civilytics-logo.svg"
+            src={import.meta.env.BASE_URL + 'civilytics-logo.svg'}
             alt="Civilytics — social science for the public good"
             className="cv-logo"
             onError={(e) => { e.target.style.display = 'none' }}

src/components/ChartPanel.jsx

@@ -23,7 +23,7 @@ export default function ChartPanel({ district, state }) {
         // National rates from static fixture (or cache from loading step)
         let nat = window.__NATIONAL_RATES__
         if (!nat) {
-          const res = await fetch('/data/national_rates.json')
+          const res = await fetch(import.meta.env.BASE_URL + 'data/national_rates.json')
           nat = await res.json()
         }
         setNationalRates(nat)