v2.1.0

v2.1.0 — log in once per machine

The CLI stored the ordinary 15-minute access token and treated it as its
login, so it stopped working a quarter of an hour after init, in every
repo. It now mints a long-lived, commit-scoped token instead.

The token is accepted only by the commit endpoints, stored hashed
server-side, and revocable from Settings or by logging out — which now
actually revokes rather than just deleting the local file.

Both the Node client and the Go port (the standalone binaries) carry the
fix. Banner reads IDEABLOCK COMMIT, and the signup link points at
ideablock.com rather than a domain with no mail authentication.