v0.78.0: Downloads that finish on their own

Downloads that finish on their own, and gaps that are really gaps. A series you add from Discover, or one whose
sources have chapters you don't, keeps downloading through rate limits and blocks until it is done. And Health no
longer calls hundreds of chapters missing when a site only numbered them differently.

Downloads that finish on their own

• Finish downloads on their own, in Admin → Settings → Updates & schedules. It is on unless you turn it off.
  A series that still has chapters to download is gone back to every 15 minutes, and again as soon as a site that was
  refusing is ready, instead of waiting for the next library update: up to ten chapters a series each time. Before, a
  series a site rate-limited half-way through an add got five chapters every six hours, and none while the site was
  cooling down.
• A chapter a site refused is tried 12 times, not 3. A rate limit or a block is a site saying "not now", so it no
  longer uses up the three tries a broken chapter gets. The cooldowns space the tries out, and once a site has refused a
  chapter twice the update also looks for it on other sources (with Look for failed chapters on other sources on, as
  it is unless you turned it off).
• An add whose first chapter the site refused is kept. The series is saved, its download card says the chapters will
  come on their own, and they do. It used to be not added at all, with nothing left to carry on from.
• The library update no longer skips a turn when another update is running at that moment. It tries again ten
  minutes later, where it used to wait a whole interval.

Fixed

• Chapter gaps counts only chapters a site lists. A series that took chapters from two sites numbering them
  differently showed a long run of chapters missing that were the same chapters under the other site's numbers: one
  series read 306 missing. Health now says those numbers apart on the row, greyed when they are all it has, as numbers
  none of its sources list, and the reader's missing-chapters notice leaves them out. Fill now still asks other
  sources for them, so a chapter some site really has is still found.

Upgrading

• Database: one new column, server_settings.finish_downloads, on by default. Additive: v0.77.x ignores it.
• Settings: four optional knobs, FINISH_DOWNLOADS_MINUTES, FINISH_DOWNLOADS_PER_SERIES,
  FINISH_DOWNLOADS_SWEEP_MAX and FINISH_DOWNLOADS_REFUSAL_CAP. The defaults need nothing set. See
  docs/CONFIGURATION.md → Downloading.
• To keep downloads as they were, turn Finish downloads on their own off.

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-0.78.0.exe
Mac with Apple silicon (M1 or newer)	Uchiyomi-0.78.0-arm64.dmg
Mac with an Intel processor	Uchiyomi-0.78.0-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.