nx_bootcap.nx

nx_bootcap.nx -- ONE boot-and-capture primitive for every organ that needs to know what the live kernel actually SAID. WHY: measuring a kernel means booting the ARTIFACT and reading its serial -- not parsing a log ABOUT the artifact, which can be stale, written by a different build, or absent entirely. That boot-and-capture block had already been copy-pasted into nx_nishios_kernel_gate and nx_kernel_adoption and was about to land in nx_kernel_census as a third copy; three copies of a measurement primitive is three chances for the rulers to silently disagree about what booted. Also owns the TWO-ROOTS resolution: the buildroot keeps the image under runtime/_hdl_build/ while the live serving root keeps it at ./ -- one name, two roots. Callers get the resolved path back so they can PRINT which artifact they actually measured; a ruler that will not say which artifact it read is not reporting a measurement. license_tier: ORIGINAL