A merged search result took its chunk_id from whichever constituent
sorted earliest in the document, while its score was the max across the
group — so the citation's identity could point at a different, less
relevant chunk. Anchor chunk_id and the content/refs fallbacks on the
max-score constituent, clip the budget window around that same chunk so
its evidence is never trimmed away, and narrow page_numbers, doc_item_refs,
and attached image bytes to the items that survive the clip.
c424f51056