Fix activity_state never running: reload segment facets per priority group
active_facets was pre-computed once before any generators ran, so the
facets.json written by the facets generator (priority 90) was never
seen by activity_state (priority 95). Reload facets at the start of
each priority group in segment mode.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>