chore(config): Migrate to ESLint v9 and Flat Config

- Migrates the legacy .eslintrc.js to the new eslint.config.js standard (Flat Config).
  - Remove legacy `.eslintrc.js` and `.eslintignore`.
  - Add `eslint.config.js` using the Flat Config format.

Author: NERDHEAD-lab

.eslintignore

@@ -0,0 +1,89 @@
+import js from '@eslint/js';
+import globals from 'globals';
+import tseslint from 'typescript-eslint';
+import reactPlugin from 'eslint-plugin-react';
+import reactHooksPlugin from 'eslint-plugin-react-hooks';
+import jsxA11yPlugin from 'eslint-plugin-jsx-a11y';
+import importPlugin from 'eslint-plugin-import';
+import prettierPlugin from 'eslint-plugin-prettier';
+import prettierConfig from 'eslint-config-prettier';
+
+export default tseslint.config(
+  {
+    ignores: ['node_modules/', 'dist/', 'sample/', '.github/'],
+  },
+
+  js.configs.recommended,
+  ...tseslint.configs.recommended,
+
+  reactPlugin.configs.flat.recommended,
+  jsxA11yPlugin.flatConfigs.recommended,
+
+  {
+    plugins: { 'react-hooks': reactHooksPlugin },
+    rules: reactHooksPlugin.configs.recommended.rules,
+  },
+
+  {
+    plugins: { prettier: prettierPlugin },
+    rules: {
+      'prettier/prettier': 'off',
+    },
+  },
+
+  {
+    files: ['**/*.{js,ts,jsx,tsx}'],
+    languageOptions: {
+      ecmaVersion: 2022,
+      sourceType: 'module',
+      globals: { ...globals.browser, ...globals.es2021, window: 'readonly' },
+    },
+    plugins: {
+      import: importPlugin,
+      prettier: prettierPlugin,
+      '@typescript-eslint': tseslint.plugin,
+    },
+    settings: {
+      'import/resolver': {
+        node: {
+          paths: ['.', 'src'],
+          extensions: ['.js', '.ts', '.jsx', '.tsx'],
+        },
+      },
+      react: {
+        version: 'detect',
+      },
+    },
+    rules: {
+      'import/extensions': 'off',
+      'import/prefer-default-export': 'off',
+      'import/no-webpack-loader-syntax': 'off',
+      'import/no-unresolved': 'off',
+      'import/no-extraneous-dependencies': 'off',
+      'no-use-before-define': 'off',
+      'no-console': 'off',
+      'no-extend-native': 'off',
+      'no-param-reassign': 'off',
+      'class-methods-use-this': 'off',
+      'dot-notation': ['error', { allowKeywords: true }],
+      'func-names': 'off',
+      'no-underscore-dangle': 'off',
+      camelcase: 'warn',
+      'no-plusplus': 'off',
+      'no-nested-ternary': 'off',
+
+      '@typescript-eslint/no-require-imports': 'off',
+      '@typescript-eslint/no-restricted-types': 'warn',
+      '@typescript-eslint/no-empty-object-type': 'off',
+      '@typescript-eslint/no-unused-expressions': 'off',
+      'no-unused-expressions': 'off',
+
+      '@typescript-eslint/no-explicit-any': 'off',
+      '@typescript-eslint/no-var-requires': 'off',
+
+      'prettier/prettier': 'off',
+    },
+  },
+
+  prettierConfig,
+);

.eslintrc.js

@@ -75,6 +75,7 @@
     "@babel/plugin-syntax-dynamic-import": "7.8.3",
     "@babel/plugin-transform-regenerator": "7.28.1",
     "@babel/preset-env": "7.28.0",
+    "@eslint/js": "^9.33.0",
     "@types/chai": "5.2.2",
     "@types/lodash": "4.17.20",
     "@types/minimist": "1.2.5",
@@ -99,6 +100,7 @@
     "eslint-plugin-prettier": "5.5.4",
     "eslint-plugin-react": "7.37.5",
     "eslint-plugin-react-hooks": "5.2.0",
+    "globals": "^16.3.0",
     "husky": "9.1.7",
     "json-loader": "0.5.7",
     "lint-staged": "16.1.5",
@@ -111,6 +113,7 @@
     "style-loader": "4.0.0",
     "ts-loader": "9.5.2",
     "typescript": "5.9.2",
+    "typescript-eslint": "^8.39.0",
     "webpack": "5.101.0",
     "webpack-bundle-analyzer": "4.10.2",
     "webpack-cli": "6.0.1"