Add script to inject prefixed vars at runtime to dist client.Dockerfile

Docker/dist/client.Dockerfile

@@ -15,5 +15,7 @@ FROM nginx:1.27.1-alpine
 
 COPY ./Docker/dist/nginx/conf.d/default.conf /etc/nginx/conf.d/default.conf
 COPY --from=build /app/dist /usr/share/nginx/html
+COPY --from=build /app/env.sh /docker-entrypoint.d/env.sh
+RUN chmod +x /docker-entrypoint.d/env.sh
 
 CMD ["nginx", "-g", "daemon off;"]