The web demo

.github/workflows/pages.yml builds the web client and deploys it to Pages on every push to main. Enable it once under Settings → Pages → Source → GitHub Actions.

It’s a sample-data demo, not a usable instance. Pages is HTTPS, and a self-hosted server on plain HTTP is mixed content that browsers block — so “Connect” can’t reach a local instance from there. Visitors get “Explore with sample data”, which runs entirely client-side.

The build-time subtlety: a Pages project site is served from /<repo>/, and the export hard-codes absolute asset URLs. client/app.config.js reads EXPO_BASE_URL so the workflow can set that prefix while the Docker build — which serves from the domain root — leaves it empty. Setting it globally would break self-hosting. A user/org site or a custom domain needs no prefix. The same value reaches the app itself as process.env.EXPO_BASE_URL, which is how the URL routing knows what to strip off the front of the path.

The other one: Pages has no rewrite rules, so /<repo>/today is a request for a file that isn’t there. The workflow copies index.html to 404.html, which is what Pages serves instead — the app boots from it, reads the path and shows the right view. The self-hosted server does the same job with a not-found handler.