Clarify checkBinRel short-circuit wording in changelog

Author: Unisay

plutus-ledger-api/changelog.d/20260527_131134_yuriy.lazaryev_issue_2243_fused_unionwith.md

@@ -2,7 +2,7 @@
 
 - Fused `unionWith` in `PlutusLedgerApi.V1.Data.Value` into two outer passes (`Map.union` + a single `Map.map`), down from the previous three. The discarded `unionVal` helper returned a full `Map CurrencySymbol (Map TokenName (These Integer Integer))` that `unionWith` then re-traversed; folding it in removes that second outer walk, and a currency present on only one side now has its token map mapped once rather than wrapped and then re-mapped. The `Map.union` lookup-and-merge core is unchanged, so this is a constant-factor improvement, not an algorithmic one.
 
-- Fused `checkBinRel` along the same shape, walking the outer `Map.union` result with `Map.all` and applying the relation directly against `0` on whichever side is missing. The walk short-circuits on the first failing pair, giving `geq` / `leq` / `gt` / `lt` early exit on inputs that violate the relation near the start of their key set.
+- Fused `checkBinRel` along the same shape, walking the outer `Map.union` with `Map.all` and applying the relation against `0` on whichever side is missing. The inner per-currency merge now sits inside the `Map.all` predicate rather than in a separate eager pass, so the walk's short-circuit on the first failing pair also skips the inner merges of every later currency — previously the whole merged structure was built before any check ran. `geq` / `leq` / `gt` / `lt` inherit this early exit.
 
 ### Removed