v0.2.0

Changed

• The GitHub Action installs the tracker from crates.io instead of building
  the checked-out repository, and gains a version input to say which release:
  the default, latest, follows crates.io, and a pinned number changes only
  when you change it. Nothing is cached — a fresh --locked install per run
  costs a minute or two and can never be stale, poisoned, or the wrong
  version. The ref you pin (@v0.2.0) now chooses only the action's own
  steps.

Fixed

• Tracking is no longer refused because of a flag it does not use. Over a
  busy year, --track --merge --background 1 failed with "the letters would
  not show" — a check meant for runs that draw, where --commits is what
  each lit day gets. Tracking never writes a commit; it works out what a
  letter day needs from the year's real peak. The GitHub Action passes no
  --merge and so never hit it, which meant the Action and the CLI disagreed
  about the same plan. Found by running the Action against a real year and
  comparing.
• A hole is called a hole again. With no background drawn, a lit day inside
  the letters reported as "background — 113 contributions, 113 too many for
  level 0", naming a shade the plan never asked for. The markdown report always
  got this right, so the text report was the one disagreeing with it.