`admin overview update` accepts --citations-file

cb4c1bf: admin overview update accepts an optional --citations-file <path> pointing at a JSON array of inline citations ({startIndex, endIndex, sourceUrl, title?, citedText}[]). The CLI validates the shape locally and forwards the array to POST /v1/orgs/:slug/overview, which persists them to knowledge_page_citations with replace-all semantics. Pairs with the regenerating-overviews skill, which now passes the file produced by the agent's response walk.