backend: harden rootless app lifecycle orchestration

docker/fedimint-ui/Dockerfile

@@ -0,0 +1,16 @@
+FROM git.tx1138.com/lfg2025/nginx:1.27.4-alpine
+
+COPY index.html /usr/share/nginx/html/index.html
+COPY nginx.conf /etc/nginx/conf.d/default.conf
+COPY assets/img/bg-network.jpg /usr/share/nginx/html/assets/img/bg-network.jpg
+COPY assets/img/app-icons/fedimint.png /usr/share/nginx/html/assets/img/app-icons/fedimint.png
+COPY assets/img/app-icons/fedimint.jpg /usr/share/nginx/html/assets/img/app-icons/fedimint.jpg
+
+RUN sed -i 's/^user  nginx;/user  root;/' /etc/nginx/nginx.conf && \
+    mkdir -p /var/cache/nginx/client_temp /var/cache/nginx/proxy_temp \
+             /var/cache/nginx/fastcgi_temp /var/cache/nginx/uwsgi_temp \
+             /var/cache/nginx/scgi_temp
+
+EXPOSE 8175
+ENTRYPOINT []
+CMD ["nginx", "-g", "daemon off;"]