MEMY-1805 marker2 ds9 (salt 4090): 75016/75016

Add dataset card, freeze manifest, and pipeline manifests (snapshot 2026-08-27)

Add extracted artifacts: 8,815 summaries, embeddings.csv, entities.json (snapshot 2026-08-27)

Add extracted artifacts: 149 summaries, embeddings.csv, entities.json (snapshot 2026-08-27)

initial commit