feat(F-048): completed feature

project/migrations/027_category_is_parent.js

@@ -0,0 +1,23 @@
+/**
+ * FIX-19: categories parent/child type.
+ * Adds is_parent flag (container category). A CHILD is a leaf and cannot
+ * contain children; only PARENT categories can contain other categories.
+ */
+
+/** @param {import('node-pg-migrate'). MigrationBuilder} pgm */
+export const up = (pgm) => {
+  pgm.sql(`ALTER TABLE categories_categories ADD COLUMN is_parent boolean NOT NULL DEFAULT false`);
+  // Migration rule: categories that already have children become parents.
+  pgm.sql(`
+    UPDATE categories_categories c
+    SET is_parent = true
+    WHERE EXISTS (
+      SELECT 1 FROM categories_categories ch WHERE ch.parent_id = c.id
+    )
+  `);
+};
+
+/** @param {import('node-pg-migrate').MigrationBuilder} pgm */
+export const down = (pgm) => {
+  pgm.sql('ALTER TABLE categories_categories DROP COLUMN IF EXISTS is_parent');
+};