nx_probe_crash_live.nx

nx_probe_crash_live.nx -- WITNESS for nx_crash.nx (v11 rung 1a): a guarded null-page deref must (a) still die by the ORIGINAL signal (shell reports 139 = 128+SIGSEGV), and (b) print the crash diagnostic on stderr naming the EXACT planted fault address 64 = 0x...40 -- which empirically proves the siginfo si_addr offset AND the kernel->NishiLang handler ABI at once. The gate greps stderr for "touching address" + "40" and asserts exit 139.