v0.2.0

New resource:
  lastping_agent -- register an agent and see its fleet state.

New on lastping_monitor:
  agent_id       -- attach a monitor to an agent (in-place update).
  assertion {}   -- assert on the ping body; a failing assertion turns a
                    success into a fail, so a job that exits zero and does
                    nothing stops reading as healthy.
  metric_guard {} -- alert when a reported numeric crosses a ceiling over a
                    window (sum/max/avg). window_s caps at 7 days.

Fixed:
  lastping_route and lastping_alert_template accept blocked and note. Six
  event types were declared where the API accepts eight, so blocked -- an
  agent waiting on a human -- could not be routed at all.