Add browser asset quality gate

eslint.config.mjs

@@ -0,0 +1,23 @@
+import js from "@eslint/js";
+import globals from "globals";
+
+export default [
+  {
+    files: ["**/*.js"],
+    ...js.configs.recommended,
+    languageOptions: {
+      ecmaVersion: 2024,
+      sourceType: "script",
+      globals: globals.browser,
+    },
+    linterOptions: {
+      reportUnusedDisableDirectives: "error",
+    },
+    rules: {
+      eqeqeq: "error",
+      "no-implicit-coercion": "error",
+      "no-var": "error",
+      "prefer-const": "error",
+    },
+  },
+];