fix: 恢复本地 Convex Auth 链路

- 修复 desktop 脚本在 Linux 下优先使用后端虚拟环境可执行文件
- 移除 Convex Auth 的本地密钥兜底，回到真实 deployment env
- 首页未登录时先跳转 /auth，避免根路由直接触发 workspace 初始化失败

wolai-frontend/src/app/page.tsx

@@ -2,6 +2,7 @@ import { redirect } from "next/navigation";
 import { isConvexEnabled } from "@/lib/convex/enabled";
 import { getAuthedConvexClient } from "@/lib/convex/route";
 import { api } from "@/lib/convex/api";
+import { convexAuthNextjsToken } from "@convex-dev/auth/nextjs/server";
 
 function makeId(): string {
   return typeof crypto.randomUUID === "function"
@@ -14,6 +15,11 @@ export default async function Home() {
     redirect("/auth");
   }
 
+  const token = await convexAuthNextjsToken();
+  if (!token) {
+    redirect("/auth");
+  }
+
   const { auth, client } = await getAuthedConvexClient();
 
   const { activeWorkspaceId } = await client.mutation(api.workspaces.ensureDefaultWorkspace, {