fromEntityZone

Creates an entity-aware Waypoint for a SINGLE EntityZone.

WHY: single-zone entity-aware waypoint so per-row routing snaps to the entity's routable node — bare-Mercator waypoints yield "Optimal route not found". Mirrors the SearchEntity branch of from (which sets entityZones = zones.map { it.engineEntityZone }) but for the one zone, so each multi-location dialog row gets its own per-zone routed distance instead of every row aggregating all zones (which would give every row the same distance).