Newton–Krylov momentum and its unpreconditioned matrix-free path are now supported within the documented single-block scope. A retained 96 x 96 x 256-cell, 144-rank channel campaign records 10,000 converged and committed steps, the restart statistics window, and an exploratory Lee–Moser DNS comparison. The run's inferred Re_tau is 202.876 against 182.088 and its skin friction is 29.3% higher, so the campaign establishes production execution rather than quantitative DNS agreement. The frozen-Jacobian preconditioner, cluster scheduling, and workspace asset lifecycle retain their experimental status.
The physical-units particle smoke fixture uses a grid large enough for the three-rank multigrid decomposition; the former 8-cells-per-axis grid left a coarse-grid partition narrower than the PETSc stencil.