Add verify-only (index-less) snapshot

chore: remove superseded legacy distribution files (top-level index + registry-2026-07); current layout is 2026-07/

add 2026-07/index/v0.2-aug-v9-gemini.npy (2026-07)

add 2026-07/index/v0.2-aug-v9-gemini.vec.json (2026-07)

add 2026-07/index/v0.2-aug-v9-gemini.meta.jsonl (2026-07)

add 2026-07/corpus/row-aligned-corpus.jsonl (2026-07)

add 2026-07/registry/texts.jsonl (2026-07)

add 2026-07/registry/chunks.jsonl (2026-07)

add 2026-07/registry/documents.jsonl (2026-07)

add 2026-07/snapshot.json (2026-07)

README for 2026-07

add registry/registry-2026-07/_manifest.json (index v0.2-aug-v9-gemini / registry-2026-07)

add registry/registry-2026-07/chunks.jsonl (index v0.2-aug-v9-gemini / registry-2026-07)

add registry/registry-2026-07/documents.jsonl (index v0.2-aug-v9-gemini / registry-2026-07)

add index/v0.2-aug-v9-gemini.meta.jsonl (index v0.2-aug-v9-gemini / registry-2026-07)

add index/v0.2-aug-v9-gemini.npy (index v0.2-aug-v9-gemini / registry-2026-07)

README for index v0.2-aug-v9-gemini / registry-2026-07

initial commit