docker_host: "-" was disabling docker access in job containers entirely,
so steps running `docker build`/`docker` directly had no daemon to talk
to. Point docker_host at the dind sibling and add a host-gateway entry
so the "dind" hostname resolves inside job containers, which run nested
on dind's own internal bridge network rather than the outer compose one.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XFsukF6FzwBxJtRGzbt28F
Stable docker-compose setup for building Rust projects on Gitea Actions.
DinD-isolated daemon, built-in cache server, capacity=4 parallel jobs,
healthcheck-gated startup. Portable to other build machines via .env.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HU4wDwdydNZpR3YkMiYYy8