Fix umami script not added

Dockerfile

@@ -5,6 +5,14 @@ WORKDIR /app/site
 ARG PUBLIC_ENABLE_SW=true
 ENV PUBLIC_ENABLE_SW=$PUBLIC_ENABLE_SW
 
+# Public, build-time config (baked into static HTML via Astro/Vite).
+ARG PUBLIC_SITE_URL
+ARG PUBLIC_UMAMI_SCRIPT_URL
+ARG PUBLIC_UMAMI_WEBSITE_ID
+ENV PUBLIC_SITE_URL=$PUBLIC_SITE_URL
+ENV PUBLIC_UMAMI_SCRIPT_URL=$PUBLIC_UMAMI_SCRIPT_URL
+ENV PUBLIC_UMAMI_WEBSITE_ID=$PUBLIC_UMAMI_WEBSITE_ID
+
 COPY site/package.json site/package-lock.json ./
 RUN npm ci --no-audit --no-fund