feat: 新增微信头像授权获取与个人中心展示功能

- 新增 `wechat-profile` 工具库，实现微信用户信息的本地存储、格式校验与授权获取逻辑
- 编写对应单元测试覆盖核心功能流程
- 重构个人中心成员组件，新增头像、昵称展示与授权触发按钮
- 更新个人中心页面，集成微信头像授权流程与状态管理

WonderQ-MiniAPP/src/lib/wechat-profile.ts

@@ -0,0 +1,49 @@
+export const WECHAT_PROFILE_KEY = "miniapp:wechat-profile";
+
+export type WechatProfile = {
+  avatarUrl: string;
+  nickName?: string;
+};
+
+function isWechatProfile(value: unknown): value is WechatProfile {
+  if (!value || typeof value !== "object") return false;
+  const profile = value as Partial<WechatProfile>;
+  return typeof profile.avatarUrl === "string" && profile.avatarUrl.trim().length > 0;
+}
+
+export function getStoredWechatProfile(): WechatProfile | null {
+  try {
+    const value = uni.getStorageSync(WECHAT_PROFILE_KEY);
+    return isWechatProfile(value) ? value : null;
+  } catch {
+    return null;
+  }
+}
+
+export function saveWechatProfile(profile: WechatProfile) {
+  if (!isWechatProfile(profile)) return;
+  uni.setStorageSync(WECHAT_PROFILE_KEY, profile);
+}
+
+export function requestWechatProfile(): Promise<WechatProfile | null> {
+  return new Promise((resolve) => {
+    if (typeof uni.getUserProfile !== "function") {
+      resolve(null);
+      return;
+    }
+
+    uni.getUserProfile({
+      provider: "weixin",
+      desc: "用于展示您的微信头像",
+      lang: "zh_CN",
+      success: (result) => {
+        const profile = {
+          avatarUrl: result.userInfo?.avatarUrl?.trim() ?? "",
+          nickName: result.userInfo?.nickName?.trim() || undefined,
+        };
+        resolve(isWechatProfile(profile) ? profile : null);
+      },
+      fail: () => resolve(null),
+    });
+  });
+}