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>