added ESLint

AGENTS.md

@@ -4,6 +4,7 @@
 
 - Nach jeder CSS-Anpassung (`*.css` Dateien) immer `cd client && npm run build` ausfuehren um zu pruefen ob der Build fehlerfrei durchlaeuft
 - Nach Aenderungen an Komponenten-Dateien (`*.tsx`) ebenfalls `npm run build` ausfuehren
+- Nach Aenderungen an TypeScript-Dateien (`*.ts`, `*.tsx`) immer `npm run lint` ausfuehren
 
 ## .NET / Backend
 

client/eslint.config.js

@@ -0,0 +1,18 @@
+// Copyright (c) 2026 Stefan Koelle (https://stefankoelle.de)
+// Licensed under the MIT License. See LICENSE file in project root for details.
+import eslint from '@eslint/js';
+import tseslint from 'typescript-eslint';
+
+export default tseslint.config(
+  eslint.configs.recommended,
+  ...tseslint.configs.recommended,
+  {
+    ignores: ['build/**', 'dist/**', 'node_modules/**'],
+  },
+  {
+    rules: {
+      '@typescript-eslint/no-unused-vars': ['warn', { argsIgnorePattern: '^_' }],
+      '@typescript-eslint/no-explicit-any': 'warn',
+    },
+  }
+);

client/package.json

@@ -10,16 +10,21 @@
     "react-dom": "^19.2.8"
   },
   "devDependencies": {
+    "@eslint/js": "^10.0.1",
     "@types/node": "^20.0.0",
     "@types/react": "^19.2.18",
     "@types/react-dom": "^19.2.4",
     "@vitejs/plugin-react": "^6.0.5",
+    "eslint": "^10.8.1",
     "typescript": "^5.0.0",
+    "typescript-eslint": "^8.66.0",
     "vite": "^8.2.1"
   },
   "scripts": {
     "dev": "vite",
     "build": "tsc && vite build",
-    "preview": "vite preview"
+    "preview": "vite preview",
+    "lint": "eslint src/",
+    "lint:fix": "eslint src/ --fix"
   }
 }