The Dockerfile installs root-level npm dependencies (for Playwright) and the
whatsapp-bridge bundle, but never builds the web/ Vite project. As a result,
'hermes dashboard' starts FastAPI on :9119 but serves a broken SPA because
hermes_cli/web_dist/ is empty and requests to /assets/index-<hash>.js 404.
Add a build step inside web/ so the Vite output is baked into the image.
Reproduce (before):
docker build -t hermes-repro -f Dockerfile .
docker run --rm -p 9119:9119 hermes-repro hermes dashboard
curl -sI http://localhost:9119/assets/ | head -1 # -> 404
After: /assets/ returns the built asset path.
