Scout v0.4.1

Scout 0.4.1 adds scout auth login: a host signs in to your Scout account through the browser, and scout web install no longer needs a download key made by hand. Keys saved by 0.4.0 keep working, and nothing needs to change before you upgrade.

What changes

• scout auth login shows a short code and opens https://console.openscout.app/device. Sign in or make an account there, then approve the terminal. The download key that comes back is saved in the macOS Keychain, in the Secret Service on Linux desktops, or otherwise in a private file. Over SSH, without a terminal, or with --no-browser, the command prints the page instead of opening it.
• scout auth status shows the signed-in account and where its key is saved, never the key. scout auth logout removes the key from this host and says where to revoke it.
• scout auth login --key - saves a key you already have. At a terminal it asks for the key without showing it. SCOUT_DIST_KEY still overrides the saved key for VMs and CI.
• scout web install with no saved key signs in first when it runs at a terminal. Without a terminal it stops with No download key. Sign in first: scout auth login.
• scout web login at a terminal is now the browser sign-in. A key piped to it is saved as before.
• When sign-in stops, the message says why: the code was denied or expired, it was already used, the account can't download the web app, or the account holds as many keys as it can.

Full notes: docs/releases.md

Full Changelog: v0.4.0...v0.4.1