Build Grafana Alloy v1.14.0 from forge mirror with embedded web UI,
replacing the upstream grafana/alloy image across all three deployments
(alloy-k8s, alloy-ringtail, alloy-tracing-ringtail). Dockerfile tested
locally, Nix build tested on ringtail. Tags are placeholders pending
first CI build.
promtail_journal_enabled tag omitted — requires systemd headers and
none of our configs use loki.source.journal.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
