Emit comma between CTEs in non-compact WITH formatting

src/formatter/select.rs

@@ -1593,7 +1593,12 @@ impl<'a> Formatter<'a> {
                 }
 
                 if !self.config.compact_ctes {
-                    lines.push(")".to_string());
+                    let is_last = i == ctes.len() - 1;
+                    lines.push(if is_last {
+                        ")".to_string()
+                    } else {
+                        "),".to_string()
+                    });
                 }
             }
 

tests/fixtures/dbt/select_cte_multi.expected

@@ -0,0 +1,18 @@
+with
+
+a as (
+
+    select 1 as x
+
+),
+b as (
+
+    select 2 as y
+
+)
+
+select *
+
+from
+    a,
+    b;

tests/fixtures/dbt/select_cte_multi.sql

@@ -0,0 +1 @@
+WITH a AS (SELECT 1 AS x), b AS (SELECT 2 AS y) SELECT * FROM a, b

tests/fixtures_test.rs

@@ -256,6 +256,11 @@ fn dbt_select_cte() {
     run_fixture(Style::Dbt, "select_cte");
 }
 
+#[test]
+fn dbt_select_cte_multi() {
+    run_fixture(Style::Dbt, "select_cte_multi");
+}
+
 // ── GitLab fixtures ─────────────────────────────────────────────────────
 
 #[test]