Remove BuildKit syntax directive and --network=host flags from admin-web, backend, and gateway Dockerfiles to simplify builds and rely on default Docker networking for dependency downloads.
Add BuildKit syntax directive and --network=host flag to npm install, go mod operations, and apk package installation to allow direct host network access during builds, bypassing Docker's default bridge network for improved reliability and performance of dependency downloads.
Add explicit Alpine 3.21 main and community repository URLs to /etc/apk/repositories. Implement 5-attempt retry loop with 3-second delays for apk update and package installation to handle transient network failures during Docker builds.
