feat(migration): drop legacy unique index on folders table

Author: jzunigax2

migrations/20260303041927-drop-legacy-unique-index-folders-plainname-parentid.js

@@ -0,0 +1,18 @@
+'use strict';
+
+/** @type {import('sequelize-cli').Migration} */
+module.exports = {
+  up: async (queryInterface) => {
+    await queryInterface.sequelize.query(`
+      DROP INDEX CONCURRENTLY IF EXISTS folders_plainname_parentid_key;
+    `);
+  },
+
+  down: async (queryInterface) => {
+    await queryInterface.sequelize.query(`
+      CREATE UNIQUE INDEX CONCURRENTLY folders_plainname_parentid_key
+      ON folders (plain_name, parent_id)
+      WHERE deleted = false;
+    `);
+  },
+};