Add ESLint + pre-commit hook and fix the issues it surfaced

package.json

@@ -11,7 +11,17 @@
     "typecheck": "tsc --noEmit",
     "test": "vitest run",
     "test:watch": "vitest",
-    "format": "prettier --write ."
+    "lint": "eslint .",
+    "lint:fix": "eslint . --fix",
+    "format": "prettier --write .",
+    "prepare": "husky"
+  },
+  "lint-staged": {
+    "*.{ts,tsx}": [
+      "eslint --fix",
+      "prettier --write"
+    ],
+    "*.{json,css,md}": "prettier --write"
   },
   "dependencies": {
     "@fontsource/ibm-plex-mono": "^5.2.7",
@@ -25,12 +35,20 @@
     "zustand": "^5.0.14"
   },
   "devDependencies": {
+    "@eslint/js": "^10.0.1",
     "@types/react": "^19.2.16",
     "@types/react-dom": "^19.2.3",
     "@vitejs/plugin-react": "^5.2.0",
+    "eslint": "^10.4.1",
+    "eslint-plugin-react-hooks": "^7.1.1",
+    "eslint-plugin-react-refresh": "^0.5.2",
+    "globals": "^17.6.0",
     "happy-dom": "^20.0.0",
+    "husky": "^9.1.7",
+    "lint-staged": "^17.0.7",
     "prettier": "^3.6.2",
     "typescript": "^5.9.2",
+    "typescript-eslint": "^8.60.1",
     "vite": "^7.1.0",
     "vite-plugin-pwa": "^1.0.3",
     "vitest": "^3.2.4"