On our 116-chunk InvoiceHub FAQ, e5-small-v2 correct query:/passage: hit Recall@5 1.0 — both-query: fell to 0.73

Author 116 InvoiceHub Support FAQ chunks × 15 gold queries (seed 20260928, API $0). Locked intfloat/e5-small-v2 and swept only prefix pairing: (A) correct query: + passage: vs (B) bare vs (C) swapped