nx_probe_castchain_live.nx

nx_probe_castchain_live.nx -- WITNESS (chained casts, 2026-08-13): `X as *u8 as i64` was HALF-APPLIED forever (one cast consumed, the dangler silently junk-skipped; then wrongly REFUSED by the discarded-expression check with a misleading cause at 15 estate sites). Post-fix: the chain is real -- final type = last cast. exit 0 = pointer survived the chain nonzero and both storage shapes work; pre-fix this file REFUSES (dangling-as fragment).