Fix code quality issues: update Cypress tests to use custom commands, fix workflow files, update documentation

cypress.config.js

@@ -1,13 +1,14 @@
-/* eslint-env node */
+/* eslint-env node, mocha */
 
 const { defineConfig } = require('cypress');
 
 module.exports = defineConfig({
   e2e: {
     baseUrl: 'http://localhost:8888',
-    setupNodeEvents() {
+    setupNodeEvents(on, config) {
       // This function can be used to register custom Cypress plugins or event listeners.
       // Currently not in use, but left for future extensibility.
+      return config;
     },
     // Add configuration for WordPress Playground
     experimentalWebKitSupport: true,