Extract salient keywords/key-phrases from text via TextRank (word co-occurrence graph + PageRank), merging adjacent high-ranked words into phrases. Pure, deterministic, model-free — extractive, NOT ML/NER or an LLM (the point: reproducible, no inference cost). English + French stopwords removed. Returns keywords[] with normalized scores (top ≈ 1). For content tagging/indexing and pre-RAG. Over 100k tokens is truncated.