Fix linting.

packages/client2/babel.config.json

@@ -7,6 +7,7 @@
 				"import": "h",
 				"export": "h"
 			}
-		]
+		],
+		"@babel/plugin-syntax-class-properties"
 	]
 }

packages/client2/eslint.config.js

@@ -0,0 +1,12 @@
+import pluginJs from "@eslint/js";
+import globals from "globals";
+import tseslint from "typescript-eslint";
+
+
+/** @type {import('eslint').Linter.Config[]} */
+export default [
+  {files: ["**/*.{js,mjs,cjs,ts,jsx,tsx}"]},
+  {languageOptions: { globals: globals.browser }},
+  pluginJs.configs.recommended,
+  ...tseslint.configs.recommended,
+];