Agents panel: usage collector for omp (Oh My Pi) — launchable as default agent but invisible to the panel

[justQrius]

For you (not part of the post)

• Post manually at the URL above, or gh auth login first, then:
  gh api graphql -f query='...' — or just paste in the browser.
• The stopgap on this machine (~/.local/bin/omarchy-omp-usage-record +
  omarchy-omp-usage.{service,timer}) can be removed once Omarchy ships the
  real collector:
  systemctl --user disable --now omarchy-omp-usage.timer
  then delete the units, the script, and ~/.local/state/omarchy/agents/usage/omp.json.