Jet gains a last field condition='velocity'. 'pressure' raises
NotImplementedError in __post_init__ before profile/amplitude validation, so a
pressure jet never reaches surface_link_velocity, tables or kernels; unknown
values raise ValueError. Amplitude stays a lattice velocity (not a flow rate);
no pressure units, field reuse, tables or kernel changes are introduced.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
(cherry picked from commit fbf6f1d122)
