Third CI failure: docker build failed on COPY --from=build /app/public
with "not found". public/ has been empty since M1 (all the default
Next.js assets were removed and nothing replaced them), and git simply
doesn't track empty directories - it only ever existed on my local
disk from before I deleted its contents in place, never in a real
checkout. Same root cause class as the tsc fix: local testing looked
fine because of leftover local state a truly fresh clone doesn't have.
