chore: update .gitignore to include .env files and add prettier for code formatting

package.json

@@ -9,8 +9,9 @@
     "preview": "vite preview",
     "build-only": "vite build",
     "type-check": "vue-tsc --build --force",
-    "lint": "eslint",
-    "lint:fix": "eslint --fix",
+    "lint": "eslint --cache",
+    "lint:fix": "eslint --fix --cache",
+    "format": "prettier . --write",
     "mcp": "ruler apply",
     "mcp:revert": "ruler revert"
   },
@@ -33,6 +34,7 @@
     "eslint-config-prettier": "^10.1.8",
     "eslint-config-vuetify": "^4.4.0",
     "npm-run-all2": "^8.0.4",
+    "prettier": "^3.8.1",
     "sass-embedded": "^1.98.0",
     "typescript": "~5.9.3",
     "vite": "^8.0.2",