3dssavesync v3.13.1

What's Changed

• Save safety: re-read before replace, read back Pokémon main, mark cut writes by @programgames in #100
• Server: refuse an empty token, ignore stray files; docs up to date by @programgames in #101
• Release 3.13.1 by @programgames in #102

Full Changelog: v3.13.0...v3.13.1