surface_link_velocity already runs jet_link_shapes; CurvedLinkSoA.
assign_surface and _prepare_blocked_boundary then ran it again with the
same jets and hits to fill the host jet cache. A private _surface_links
returns (velocity, aperture, shape, jet_id) from the one call; both
callers use it. surface_link_velocity keeps its two-value public
contract (now a thin wrapper). Same values, same validation order, same
cache contents; host geometry preparation only.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
