Ingest selected papers into the project library — adds them to .paic/library/selected.yaml, downloads PDFs/markdowns via the appropriate per-platform tool (arxiv MCP for arxiv; paper-search-mcp for pubmed / biorxiv / openalex / etc.), names files as `NNN_title.<ext>` under .paic/library/pdfs/, and (optionally) syncs the batch to Zotero via zotero-mcp. Use after /paic-search when the user picks which papers to keep.
