Add npm run deploy for Cloudflare Pages direct upload
The git remote is on tangled.org, so Cloudflare's git-connected builds
aren't available. Add a deploy script that builds locally and pushes dist/
to the atmot Pages project via Wrangler direct upload.
Pin --branch=trunk so deployments always land in production regardless of
the local working branch; without it, deploying from a feature branch
produces a preview URL and leaves the live site unchanged. Pin wrangler as
a devDependency for reproducibility, ignore .wrangler/ state, and document
the flow in the README.