refactor(format): subqueries and CTE lists on Doc-IR; fix CTE commas with trailing style

pkg/format/dml_test.go

@@ -710,3 +710,21 @@ func TestSelectWrapBrokenHonoursCommaStyle(t *testing.T) {
 		t.Errorf("leading commas expected when broken:\n%s", got)
 	}
 }
+
+func TestMultiCTETrailingCommas(t *testing.T) {
+	src := "with a as (select 1), b as (select 2) select * from a, b"
+	st := config.Default()
+	st.Commas = config.CommaTrailing
+	got := File(parser.Parse(src), st)
+	if !strings.Contains(got, "a AS (") || !strings.Contains(got, "),\n") {
+		t.Errorf("trailing comma between CTEs expected:\n%s", got)
+	}
+	if err := VerifySafe(src, got, st); err != nil {
+		t.Errorf("safety gate: %v\n%s", err, got)
+	}
+	st.Commas = config.CommaLeading
+	got = File(parser.Parse(src), st)
+	if !strings.Contains(got, ",b AS (") {
+		t.Errorf("leading comma expected:\n%s", got)
+	}
+}