Add an infra-owned image (Playwright base + google-chrome-stable) + its GHA
build workflow. The bundled Chromium ships proprietary codecs compiled out, so
H.264/AAC video (Instagram Reels, X, most .mp4) fails in the noVNC view with
MEDIA_ERR_SRC_NOT_SUPPORTED; only real Google Chrome carries those codecs
(libffmpeg swap + Chrome-for-Testing both ruled out). This commit only builds
the image (→ ghcr.io/viktorbarzin/chrome-service-browser); a follow-up flips
main.tf's launch to it once the image exists + is public.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>