Without postcss.config.mjs, @tailwindcss/postcss never ran during
'next build', producing a CSS bundle with only @font-face rules (33KB)
and zero Tailwind utility classes. The UI rendered as unstyled HTML
(black background, white text, no spacing).
- Add web/postcss.config.mjs wiring @tailwindcss/postcss (matches the
pattern used by sibling repos like ChronoMind)
- Copy postcss.config.mjs into the web Docker build stage so 'pnpm run
build' can resolve it
