Add language assistant features and improve encryption handling: Implement a new route and controller method for sending messages to the language assistant, enhancing user interaction within lessons. Update the encryption utility to support both base64 and hex formats for better compatibility with existing data. Enhance localization files to include new terms related to the language assistant in English, German, and Spanish, improving user experience across languages.

backend/migrations/20260325010000-expand-user-param-value-to-text.cjs

@@ -0,0 +1,18 @@
+'use strict';
+
+/** @type {import('sequelize-cli').Migration} */
+module.exports = {
+  async up(queryInterface) {
+    await queryInterface.sequelize.query(`
+      ALTER TABLE community.user_param
+      ALTER COLUMN value TYPE TEXT;
+    `);
+  },
+
+  async down(queryInterface) {
+    await queryInterface.sequelize.query(`
+      ALTER TABLE community.user_param
+      ALTER COLUMN value TYPE VARCHAR(255);
+    `);
+  }
+};