point --epic help at the adhoc sentinel (#2130) (#2169)
Epic vergil-project/.github#85, Task 12. The living-doc standing->ad-hoc sweep found nothing to rename: no living doc or site-docs guide describes the epic/task model (it lived only in the epic specs), and CLAUDE.md's 'standing' is the no-direct-commits policy, unrelated. The one real user-facing item: the --epic help in vrg-issue-create and vrg-epic-move still showed 'standing' as the sentinel; point users at 'adhoc' (standing keeps working as the silent deprecated alias). The comprehensive issue-management site-docs guide the sweep revealed as missing is filed as its own task (#2168) under this epic.