FreeWheel (MRM) ads from a single FreewheelConfig, two
ways to run it: the native FreeWheel SDK (FreewheelAdsProvider —
FW's own AdManager.js makes the request and plays its slot schedule), or the
FW server as VMAP through IMA (no FreeWheel SDK needed). Pick one per
player; the pre/mid/post-roll UI is identical either way.