Clear reading entry and safer PDF access

NUU Surf

Clear reading entry and safer PDF access
Changed
Open NUU Docs from the Surf landing to manage sources.
Added
The user menu has suggestions, bug reports, and the changelog. The reader shows a live link to its Docs source.
Fixed
PDF proxy requests require sign-in, refuse production loopback hosts and redirects, and stop at 32 MiB.
Fixed
The old user document APIs check the signed-in owner and reject invalid path IDs.
All updates of NUU Surf