🔧 chore: 升级转译目标至 Chrome 90+ 并引入 browserslist 配置

- package.json 新增 browserslist 字段（defaults, Chrome >= 90, not dead）
- transpile-dist-js.js 从 browserslist 动态解析目标，不再硬编码 Chrome 77
- 减少不必要的语法降级，输出更精简的现代 JS

package.json

@@ -85,6 +85,11 @@
     "webpack-cli": "^5.1.4",
     "workbox-webpack-plugin": "^7.0.0"
   },
+  "browserslist": [
+    "defaults",
+    "Chrome >= 90",
+    "not dead"
+  ],
   "engines": {
     "node": ">=18.0.0",
     "npm": ">=8.0.0"