Runtime driver

Owner: linstabpy.driver.run.

The driver package __init__ exports nothing so import linstabpy.driver never pulls PETSc. cli.py handles --version without initializing PETSc, then imports driver.run.

Files

File	Role
run.py	Pipeline stages, run()
cli.py	Cache-aware entry, --version
payload.py	build_runtime_payload, RUNTIME_NPZ_CONTRACT_KEYS
io.py	NPZ/sidecar write. Does not import the driver
preflight.py	Non-blocking warnings (dissipation mismatches, shadowed factor_backend, band-marking trap, freestream scale, opaque MUMPS INFOG(1))

Dirichlet reduction

Stability may drop Dirichlet-constrained DOFs from the operator and Chu weights, then scatter eigenvectors back into the full vector. Constrained entries stay zero. reduce_dirichlet_set chooses which index set is removed.

Acceptance

stability.acceptance applies residual, target-distance, and omega-bound rules. Conjugate-aware mode admits the conjugate partner of a real-valued baseflow at the same target_distance_max.