v0.79.0: Downloads that keep going

A site that is cooling down no longer holds a series up. When a site rate-limits or blocks the server, the series
that use it keep downloading from the other sources they follow, and the chapters only that site has are kept for when
it can answer, wherever the download started: an add from Discover, Find missing chapters, or the scheduled checks.

Downloads that keep going

• A series whose main site is cooling down downloads from the other sources it follows. The library update and
  Finish downloads on their own used to line up every series behind its main site and wait out the cooldown, even
  when another source had the chapters.
• The chapters only the cooling site lists stay on the list. They used to drop out until the site answered again,
  so the series looked caught up. Now they wait, and they are fetched as soon as the cooldown ends.
• A site that refuses a chapter's page list is treated as a refusal, like refused images. The chapter gets the
  twelve tries a refused chapter gets, and the site is given its cooldown, instead of three tries as a broken chapter.
• Adding from Discover while the site is cooling down keeps the series, and so does an add whose page list the site
  refuses. Its chapters come on their own. It used to answer "try a different source" and add nothing.
• Find missing chapters takes a chapter from another followed source when its own site is cooling down. A chapter
  no other source has downloads on its own when the site is ready, and the dialog says so. A download that every source
  refuses part-way hands the rest on the same way.
• The finishing runs give way. The library update, the nightly repair, Fix everything and Find other
  sources no longer wait for a finishing run to end. It stops at the next chapter and picks up after them.

Upgrading

• Database: one new column, lib_series.finish_after. Additive: v0.78.x ignores it.
• API: POST /api/sources/fetch can skip a number with the reason later. Its site is cooling down, no other
  followed source lists it, and Finish downloads on their own will fetch it. See docs/api.md.

Uchiyomi Desktop (beta): downloads

Uchiyomi as a program on your own computer, for Windows and Mac. On first launch it asks how you want to
use it: on this computer (the whole app, with the library in a folder on your PC and no Docker or
server to run) or connected to your own Uchiyomi server (a window onto the server you already run).

Your computer	Download
Windows (x64)	Uchiyomi-Setup-0.79.0.exe
Mac with Apple silicon (M1 or newer)	Uchiyomi-0.79.0-arm64.dmg
Mac with an Intel processor	Uchiyomi-0.79.0-x64.dmg

Only those three are for you: the .zip, .blockmap and latest*.yml files are what the app's own updater
reads. The same installers are also here under names without a version (Uchiyomi-Setup.exe,
Uchiyomi-mac-arm64.dmg, Uchiyomi-mac-x64.dmg), which always lead to the newest release.

The app is not signed yet, so the first launch takes one extra step:

• Windows: "Windows protected your PC" appears once. Choose More info, then Run anyway. A PC
  with Smart App Control turned on blocks unsigned apps with no way past it; use the Docker install there.
• macOS: open the dmg and drag Uchiyomi to Applications. The first time you open it, macOS refuses;
  go to System Settings → Privacy & Security and choose Open Anyway.

Windows installs updates by itself. A Mac cannot update an unsigned app, so there a new version is a new
download; the menu-bar icon and Admin → Health say when one is out.

Step by step, with pictures -- which file, the first launch on each system, the two ways to use it, adding
sources, updates, backups, where files live and uninstalling:
the desktop guide.