Slice 2 of the #319 retirement. The blueprint leg now carries both run
shapes: a bias signal via run_signal_r, a no-bias measurement blueprint
(>=1 declared tap) via run_measurement — record lines byte-identical to
run's. --override NODE.PARAM=VALUE (repeatable) is the one deliberate
sugar residue: validated through the shared override_paths prose, the
closed-guard runs on the reopened probe (space == override set), values
bind in reopened param_space order so the manifest records them raw under
params ("what varied"). A measurement blueprint refuses --override
explicitly (its space is not wrap_r-wrapped) rather than dropping it
silently.
refs #319
claude
da19e27b6a