fix(boaRecon): add method=Check filter to matchElectronicReturn

Electronic returns only apply to checks, but the matcher was not
filtering by method, so an electronic return could incorrectly
match against a same-amount, bank-confirmed ACH record.

src/boaRecon.js

@@ -236,6 +236,7 @@ export function matchCheckTransaction(classified, payments, refDateISO) {
 export function matchElectronicReturn(classified, payments, refDateISO) {
   const candidates = payments.filter(
     (p) =>
+      p.method === "Check" &&
       (p.clear_status === "Cleared" || p.clear_status === "Returned") &&
       amountsEqual(p.amount_usd, classified.amount) &&
       issuedWithinDays(p, refDateISO, 120)

tests/boaRecon.test.js

@@ -271,6 +271,25 @@ test("electronic return: unique amount among bank-confirmed payments matches", (
   assert.equal(m.payment.check_number, "1001");
 });
 
+test("electronic return: never matches ACH payments", () => {
+  const achCleared = payment({
+    method: "ACH",
+    check_number: "21222000264",
+    amount_usd: 3992.15,
+    clear_status: "Cleared",
+    pk: "payment#21222000264",
+  });
+  const checkCleared = payment({
+    check_number: "1001",
+    amount_usd: 3992.15,
+    clear_status: "Cleared",
+  });
+  // Only the Check should be a candidate — ACH is excluded.
+  const m = matchElectronicReturn({ amount: 3992.15 }, [achCleared, checkCleared], "2026-07-20");
+  assert.equal(m.payment.check_number, "1001");
+  assert.equal(m.matchedBy, "amount+cleared");
+});
+
 test("electronic return: ambiguity is unmatched", () => {
   const payments = [
     payment({ check_number: "1001", amount_usd: 2500, clear_status: "Cleared" }),