Published hosted_url, pdf_url, epub_url, and all links in the reader
page now use {space}.rspace.online/rpubs/... (subdomain form) instead
of path-scoped rspace.online/{space}/rpubs/... — matching the site
convention that space slugs always appear as subdomains.
The server already rewrites subdomain → path-scope internally for
routing, so Hono route mounts stay the same.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>