Update eslint to flat config

eslint.config.js

@@ -1,22 +1,28 @@
-// eslint.config.js
-export default {
-    env: {
-      node: true,
-      es2021: true,
-    },
-    extends: [
-      'eslint:recommended',
-      'plugin:prettier/recommended',
-    ],
-    parserOptions: {
-      ecmaVersion: 'latest',
-      sourceType: 'module',
+// eslint.config.js (flat config)
+import configRecommended from "eslint-config-eslint";
+import configPrettier from "eslint-config-prettier";
+import pluginPrettier from "eslint-plugin-prettier";
+import globals from "globals";
+import unusedImports from "eslint-plugin-unused-imports";
+import js from "@eslint/js";
+
+export default [
+  {
+    languageOptions: {
+      ecmaVersion: "latest",
+      sourceType: "module",
+      globals: {
+        ...globals.node,
+      },
     },
     rules: {
-      // Add your custom rules here
-      'no-console': 'warn',
-      'no-unused-vars': 'warn',
-      // Example: 'semi': ['error', 'always']
+      "no-console": "warn",
+      "no-unused-vars": "warn",
+      "unused-imports/no-unused-imports": 1,
     },
-  };
-  
+  },
+  js.configs.recommended,
+  pluginPrettier.configs.recommended,
+  configPrettier,
+  unusedImports.configs.recommended,
+];