chore(tooling): modernize Next verification setup

eslint.config.mjs

@@ -0,0 +1,9 @@
+import { defineConfig, globalIgnores } from 'eslint/config';
+import nextVitals from 'eslint-config-next/core-web-vitals';
+import nextTypeScript from 'eslint-config-next/typescript';
+
+export default defineConfig([
+  ...nextVitals,
+  ...nextTypeScript,
+  globalIgnores(['.next/**', 'out/**', 'node_modules/**', 'next-env.d.ts']),
+]);