WebKit takes *.localhost to loopback through GLib and ignores /etc/hosts, so
the container shares Traefik's network namespace. The webkit project only
exists with PLAYWRIGHT_WEBKIT=1, so test-frontend stays Chromium only.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WgBfkm4rCmtd1T4vHWjEPx