chore: remove ESLint configuration and ignore files

- Deleted .eslintignore and .eslintrc.cjs files as they are no longer needed.
- Updated package.json lint scripts to simplify ESLint usage.
- Cleaned up pnpm-lock.yaml by removing unused ESLint-related dependencies.

Author: ryota-murakami

.eslintignore

@@ -0,0 +1,38 @@
+/**
+ * ESLint Flat Configuration
+ * @see https://eslint.org/docs/latest/use/configure/configuration-files
+ *
+ * Migrated from .eslintrc.cjs to ESLint v9 flat config format.
+ */
+import tsPrefixer from 'eslint-config-ts-prefixer'
+import jsxA11y from 'eslint-plugin-jsx-a11y'
+import reactHooks from 'eslint-plugin-react-hooks'
+
+export default [
+  // ─────────────────────────────────────────────────────────────
+  // Global ignores (migrated from .eslintignore)
+  // ─────────────────────────────────────────────────────────────
+  {
+    ignores: [
+      '.vscode/**',
+      '.github/**',
+      // Note: node_modules, build, dist, .git, .idea are already ignored by ts-prefixer
+    ],
+  },
+
+  // ─────────────────────────────────────────────────────────────
+  // Base configuration from eslint-config-ts-prefixer
+  // Includes: TypeScript parser/plugin, eslint-plugin-import, projectService
+  // ─────────────────────────────────────────────────────────────
+  ...tsPrefixer,
+
+  // ─────────────────────────────────────────────────────────────
+  // Accessibility rules (jsx-a11y)
+  // ─────────────────────────────────────────────────────────────
+  jsxA11y.flatConfigs.recommended,
+
+  // ─────────────────────────────────────────────────────────────
+  // React Hooks rules
+  // ─────────────────────────────────────────────────────────────
+  reactHooks.configs.flat['recommended-latest'],
+]

.eslintrc.cjs

@@ -16,8 +16,8 @@
     "serve": "serve dist",
     "test": "vitest --run",
     "test:watch": "vitest",
-    "lint": "eslint src --ext .ts,.tsx,.js,jsx.cjs",
-    "lint:fix": "eslint src --ext .ts,.tsx,.js,jsx,cjs --fix",
+    "lint": "eslint src",
+    "lint:fix": "eslint src --fix",
     "typecheck": "tsc --noEmit",
     "prettier": "prettier --ignore-unknown --write .",
     "clean": "rimraf node_modules pnpm-lock.yaml dist",
@@ -58,11 +58,9 @@
     "eslint": "^9.39.2",
     "eslint-config-prettier": "^10.1.8",
     "eslint-config-ts-prefixer": "^4.1.0",
-    "eslint-config-typescript": "^3.0.0",
     "eslint-import-resolver-typescript": "^4.4.4",
     "eslint-plugin-import": "^2.32.0",
     "eslint-plugin-jsx-a11y": "^6.10.2",
-    "eslint-plugin-prettier": "^5.5.4",
     "eslint-plugin-react-hooks": "^7.0.1",
     "husky": "^9.1.7",
     "jsdom": "^27.3.0",

eslint.config.mjs

@@ -1,5 +1,5 @@
-import { createApi } from '@reduxjs/toolkit/query/react'
 import type { BaseQueryFn } from '@reduxjs/toolkit/query'
+import { createApi } from '@reduxjs/toolkit/query/react'
 import axios from 'axios'
 import type { AxiosRequestConfig, AxiosError } from 'axios'
 

package.json

@@ -22,7 +22,7 @@
     "vite.config.ts",
     "vitest.config.ts",
     "postcss.config.js",
-    ".eslintrc.cjs",
+    "eslint.config.mjs",
     "./src",
     "./@types"
   ]