Enrich a Mind from keyword web search (alias)

Convenience alias for the keyword-search mode of POST /v1/minds/{mindId}/knowledge (addMindKnowledge): it validates that keywords is a non-empty array and then forwards the same request to that endpoint, so behaviour, limits, and the 202 response are identical. Use it when you want an endpoint that only accepts keyword enrichment; use the main endpoint if you also add links or files. Send Content-Type: application/json with keywords (and optionally regeneratePrompt, default true) and nothing else: because the request is forwarded verbatim, a body that also contains file is treated as a remote-file upload by the target handler. Keywords are trimmed, de-duplicated, and capped at 15 (extra keywords are silently dropped). The search runs in the background; poll GET /v1/minds/{mindId}/training for progress. Access: you must be able to edit the Mind (owner, direct collaborator, or member of the team the Mind is shared with); other Minds answer 404 Mind not found or access denied.