refactor(auth): 按扁平接口简化鉴权解析

登录/刷新/发短信直接解析根级字段，移除 data 包装与 mergeUser 等多余逻辑。
首页侧栏用户信息随 localStorage 与 chatone-user-changed 更新，优先展示 nickname。

Made-with: Cursor

src/pages/index.tsx

@@ -1,5 +1,5 @@
 import type { CSSProperties } from "react";
-import { useEffect, useMemo, useRef, useState } from "react";
+import { useEffect, useMemo, useRef, useState, useSyncExternalStore } from "react";
 import {
   ArrowUpOutlined,
   LogoutOutlined,
@@ -44,13 +44,13 @@ type UiMessage = {
   thinking?: string;
 };
 
-function readStoredUserProfile(): { displayName: string; avatar?: string } {
+function parseStoredUserProfileJson(raw: string | null): { displayName: string; avatar?: string } {
   try {
-    const raw = window.localStorage.getItem(USER_KEY);
     if (!raw) return { displayName: "用户" };
     const u = JSON.parse(raw) as Record<string, unknown>;
+    const nickname = typeof u.nickname === "string" && u.nickname.trim() ? u.nickname.trim() : "";
     const displayName =
-      (typeof u.nickname === "string" && u.nickname) ||
+      nickname ||
       (typeof u.name === "string" && u.name) ||
       (typeof u.username === "string" && u.username) ||
       (typeof u.phone === "string" && u.phone) ||
@@ -65,6 +65,19 @@ function readStoredUserProfile(): { displayName: string; avatar?: string } {
   }
 }
 
+/** 与 `persistUser` 内触发的 `chatone-user-changed` 及跨标签 `storage` 对齐，用于刷新侧栏昵称 */
+function subscribeUserProfile(onChange: () => void) {
+  const onStorage = (e: StorageEvent) => {
+    if (e.key === USER_KEY || e.key === null) onChange();
+  };
+  window.addEventListener("chatone-user-changed", onChange);
+  window.addEventListener("storage", onStorage);
+  return () => {
+    window.removeEventListener("chatone-user-changed", onChange);
+    window.removeEventListener("storage", onStorage);
+  };
+}
+
 const INITIAL_MESSAGES: UiMessage[] = [
   {
     id: "init-assistant",
@@ -108,7 +121,15 @@ export default function HomePage() {
     [],
   );
 
-  const userProfile = useMemo(() => readStoredUserProfile(), []);
+  const userJsonSnapshot = useSyncExternalStore(
+    subscribeUserProfile,
+    () => window.localStorage.getItem(USER_KEY) ?? "",
+    () => "",
+  );
+  const userProfile = useMemo(
+    () => parseStoredUserProfileJson(userJsonSnapshot || null),
+    [userJsonSnapshot],
+  );
 
   /** 用户信息下拉：略增大行高与项间距 */
   const userMenuItemStyle: CSSProperties = {