Alongside the existing 'least recently used' section, surface two more
rankings so users can see which of their agent-created skills actually
get exercised:
- 'most used (top 5)' — sorted by use_count descending. Hidden when every
skill has use_count=0 (noise suppression on fresh installs).
- 'least used (top 5)' — sorted by use_count ascending. Always shown
when the catalog is non-empty.
use_count started tracking real agent skill activation in PR #17932
(bump_use wired into skill_view tool + slash invocation + --skill
preload), so these rankings are now meaningful.
Tests: 3 new in tests/hermes_cli/test_curator_status.py — happy path
with mixed use_counts, zero-use suppression of the most-used section,
and the no-skills clean-empty case.