feat: 添加Tailwind CSS支持并修复URL拼接问题

添加Tailwind CSS及相关配置
修复多个爬虫服务中的URL拼接问题，避免双斜杠
调整前端导航菜单项顺序

frontend/package.json

@@ -17,9 +17,13 @@
     "vue": "^3.5.24"
   },
   "devDependencies": {
+    "@tailwindcss/postcss": "^4.1.18",
     "@types/node": "^24.10.1",
     "@vitejs/plugin-vue": "^6.0.1",
     "@vue/tsconfig": "^0.8.1",
+    "autoprefixer": "^10.4.23",
+    "postcss": "^8.5.6",
+    "tailwindcss": "^4.1.18",
     "typescript": "~5.9.3",
     "vite": "^7.2.4",
     "vue-tsc": "^3.1.4"