Made In Heaven

The second Senpwai 3 beta brings a new Cloudflare-free source and handles
browser trouble better.

• New source, AnimeHeaven: Direct downloads, no Cloudflare, no browser
  window. 😇
• New defaults: AnimeHeaven and Nyaa are on by default. AnimePahe and Tokyo
  Insider can be enabled in Settings → Sources & Search. Coming from beta 1?
  Enable AnimeHeaven there.
• Faster planning: AnimeHeaven links are fetched in parallel, tunable under
  Request Parallelism.
• Browser trouble, handled: If the built-in browser can't open, Senpwai
  offers to disable the sources that need it.
• Fewer connection errors: Fixed connections to HTTP/1.1-only servers.

This is still a beta, so expect and report bugs. Windows installers are unsigned
and the macOS app is ad-hoc signed; your system may ask you to approve the first
launch.