refactor(components): 优化代码结构和可维护性

- 在 auth.tsx 中引入 Path 常量，以便统一管理路由路径
- 在 server.ts 中移除了未使用的 DEFAULT_GA_ID 常量，减少冗余代码

app/components/auth.tsx

@@ -3,6 +3,7 @@ import { IconButton } from "./button";
 import { useState, useEffect } from "react";
 import { useNavigate } from "react-router-dom";
 import { useAccessStore } from "../store";
+import { Path } from "../constant";
 import Locale from "../locales";
 import Delete from "../icons/close.svg";
 import Arrow from "../icons/arrow.svg";

app/config/server.ts

@@ -1,5 +1,5 @@
 import md5 from "spark-md5";
-import { DEFAULT_MODELS, DEFAULT_GA_ID } from "../constant";
+import { DEFAULT_MODELS } from "../constant";
 import { isGPT4Model } from "../utils/model";
 
 declare global {