buildFeedWhere trusted filterMunicipality without intersecting the
creator's current municipality scope when accessibleMunicipalityIds is
non-null (advisor). An advisor removed from a municipality after creating
a pinned feed kept serving its activities. Now the read re-derives the
creator's scope on every request (fail-closed, aligned with C16) and
intersects it into the where clause via the canonical
advisorMunicipalityScopeWhere fragment.
Int tests cover: advisor in-scope lists, advisor removed stops serving,
coordinator (unrestricted) unchanged. No migration (config/consulta only).
