test(tier1): nginx web image serving the built SPA

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

testing/web.Dockerfile

@@ -0,0 +1,12 @@
+FROM node:20-slim AS build
+WORKDIR /app
+COPY frontend/package.json frontend/package-lock.json /app/
+RUN npm ci
+COPY frontend/ /app/
+ENV VITE_APP_NAME="RFC Tier1"
+RUN npm run build
+
+FROM nginx:1.27-alpine
+COPY testing/web.nginx.conf /etc/nginx/conf.d/default.conf
+COPY --from=build /app/dist /usr/share/nginx/html
+EXPOSE 80