nx_elseif_desync_probe.nx

nx_elseif_desync_probe.nx -- PROBE for debt seq358 "else-if branch with MULTILINE body desyncs nx_parse: subsequent funcs FUSE into the current one as empty stubs -> binary compiles clean and exits 0 SILENTLY doing nothing". Same live-or-fixed oracle as the landmine probes. CONTRACT: exit 0 => ROOT-FIXED; non-zero OR build-failure (bogus arity error) => STILL LIVE. The discriminator: `second` is DEFINED AFTER a func that ends in an else-if with a multiline body, and `second` takes >=1 arg (the debt says the arity check surfaces the desync only then). If the desync is live, `second` fuses into `first` as statements and is emitted as an empty stub returning 0, so second(5) != 105. license_tier: ORIGINAL No hw writes (Rule 26). expect_exit: 0