categoryLabel (string) → categoryLabels (list). Enables multi-crop queries (e.g. "Mg deficiency in tomato and cucumber").\n\n## Changes\n\n- chatqna align_inputs: read categoryLabels (list) instead of categoryLabel (string)\n- retriever invoke: same change in the filter_data path\n- run_eval.py: send categoryLabels in the chatqna payload\n- gold_dataset.example.json: updated schema with multi-crop example\n- test_label_contract.py: +4 multi-label tests (22 total)\n\n## No backward compat\n\nClean schema migration. No categoryLabel fallback.\n\n## Filter strategy\n\nRetriever default is ARANGO_FILTER_STRATEGY="OR" — any matching label passes. Correct for multi-crop (a Tomato chunk matches ["Tomato","Cucumber"]).