Agent Skills: paper-cluster-by-theme

Groups a set of kept papers into 2-5 thematic clusters before synthesis, using abstract semantics + matched-keyword overlap. Names each cluster with a short noun phrase that describes what the cluster argues, not just the topic. Surfaces an "outliers" bucket for single-paper themes that don't fit. Domain-neutral - usable for any literature-scan workflow. Use after relevance filtering and before writing the synthesis report. Trigger keywords - cluster papers, group by theme, thematic clusters, paper themes, organize papers.