Hoard 2.1.0

A setup assistant, so nobody needs a command line or has to guess what to do first.

• The setup assistant opens the first time you start Hoard, and any time from Settings. It covers
  the browser Hoard signs in with, which stores you use, your Payhip shops, signing in to each store,
  where downloads go, and bringing over Hoard 1.x.
• No more playwright install: if Hoard needs its own browser, one button installs it, with
  progress. On Windows, Hoard uses Microsoft Edge, which is already there. If a store is ever read
  without the browser installed, the message says what to do instead of showing Playwright's error.
• Signing in without your saved passwords: Hoard's window is its own browser, so it doesn't have
  what your usual browser saved. The assistant shows where to copy your password from (Chrome, Edge,
  Firefox, Safari, password managers) and other ways in: password reset, Google or Discord sign-in, and
  passkeys on Windows Hello or your phone.
• Links from emails: when a store emails a sign-in or "is this you?" link, paste it into the
  assistant and it opens in Hoard's window, rather than signing in your usual browser. Only links on
  that store's own site are accepted.
• Stores you don't use are hidden, from the tabs, the Stores panel, the grid and Refresh all.
• New install-browser command, for the command line.