v0.2.0

Added

• SSH authentication via the ssh-agent (SSH_AUTH_SOCK): the private key never
  leaves the agent, and an encrypted key works. The inventory key: is now an
  optional override, tried before the agent (ADR-0026).

Changed

• key: is no longer required in the inventory; authentication falls back to the
  ssh-agent when it is absent.

Fixed

• Expand ~ in the inventory key: path (and --known-hosts), so the documented
  ~/.ssh/… examples connect instead of failing with read key: no such file.