Adds a lightweight alternative to the corpus_builder + clip_search pipeline
that skips CLIP embeddings, motion scores, and index files. Uses the same
StockSource adapter protocol so it works with all providers (Pexels,
Archive.org, NASA, Wikimedia, Unsplash). Asset-director skill now documents
both fast path (direct search) and standard path (corpus + CLIP retrieval).
Pipeline manifest updated to make corpus tools optional.
calesthio
0999eaddc7