nx_etg_probe_cpu_test.nx

nx_etg_probe_cpu_test.nx -- KAT for E3 first real CPU probe. Verifies: T1 Classifier taxonomy: each NX_ETG_OUTCOME_* the classifier can emit is reachable on a deterministic synthetic input. T2 Boundary cases: claim==0, measured==0 -> INCONCLUSIVE. T3 CONFIRMED band: measured within (claim - low%, claim + high%). T4 FALSIFIED: measured > claim * (1 + high/1000). T5 VENDOR_LIED_OMISSION: measured < claim * (1 - low/1000). T6 Real probe end-to-end: invokes nx_calibrate_run on qemu-RV64 with a deliberately permissive claim (100,000 ns) and asserts the emitted entry is valid + the outcome is one of the allowed verdicts (CONFIRMED / VENDOR_LIED_OMISSION / FALSIFIED). The exact value of measured is non-deterministic under qemu, so we don't assert on it -- we assert the PIPELINE is real.