Add prettier. Format.

package.json

@@ -16,7 +16,8 @@
     "test:e2e": "playwright test",
     "preview": "vite preview",
     "electron": "npm run build && electron apps/electron/main.mjs",
-    "cap:sync": "npm run build && npm --prefix apps/capacitor exec cap sync"
+    "cap:sync": "npm run build && npm --prefix apps/capacitor exec cap sync",
+    "format": "prettier --write \"**/*.{js,jsx,ts,tsx,json,css,md}\""
   },
   "dependencies": {
     "@capacitor/app": "^8.0.0",
@@ -46,6 +47,7 @@
     "@vue/tsconfig": "^0.9.1",
     "electron": "^43.1.1",
     "happy-dom": "^20.10.6",
+    "prettier": "^3.9.6",
     "typescript": "~6.0.2",
     "vite": "^8.1.1",
     "vitest": "^3.2.4",