관리자 레이아웃과 네비게이션 정리

db/migrations/019_dedupe_navigation_items.sql

@@ -0,0 +1,23 @@
+-- 반복 마이그레이션 실행으로 생긴 동일 위치·상위·라벨·URL 메뉴 중복 정리
+WITH ranked_navigation AS (
+  SELECT
+    id,
+    row_number() OVER (
+      PARTITION BY location, COALESCE(parent_id::text, ''), label, url
+      ORDER BY
+        CASE WHEN is_folder THEN 0 ELSE 1 END,
+        sort_order ASC,
+        created_at ASC,
+        id ASC
+    ) AS row_rank
+  FROM navigation_items
+)
+DELETE FROM navigation_items
+WHERE id IN (
+  SELECT id
+  FROM ranked_navigation
+  WHERE row_rank > 1
+);
+
+CREATE UNIQUE INDEX IF NOT EXISTS navigation_items_location_parent_label_url_unique_idx
+  ON navigation_items (location, COALESCE(parent_id::text, ''), label, url);