add linting for cypress tests

eslint.config.mjs

@@ -0,0 +1,21 @@
+import globals from 'globals'
+import pluginJs from '@eslint/js'
+import pluginCypress from 'eslint-plugin-cypress/flat'
+import pluginPrettier from 'eslint-plugin-prettier/recommended'
+
+// NOTE: This config is only used for running ESLint on the Cypress tests. Frontend and backend use their own configs.
+
+/** @type {import('eslint').Linter.Config[]} */
+export default [
+  {
+    languageOptions: { globals: globals.browser },
+  },
+
+  {
+    files: ['cypress/*.js'],
+    rules: pluginJs.configs.recommended.rules,
+  },
+
+  pluginCypress.configs.recommended,
+  pluginPrettier,
+]