feat(membership): 实现会员系统和购买流程

- 创建 MembershipModalContext 统一管理会员弹窗
- 优化 MembershipModal 产品套餐展示和购买流程
- 集成 RevenueCat SDK 并初始化内购功能
- 在个人中心添加会员 Banner，引导非会员用户订阅
- 修复日志工具的循环引用问题，确保错误信息正确记录
- 版本更新至 1.0.20

新增了完整的会员购买流程，包括套餐选择、购买确认、购买恢复等功能。会员 Banner 仅对非会员用户展示，已是会员的用户不会看到。同时优化了错误日志记录，避免循环引用导致的序列化失败。

app/_layout.tsx

@@ -32,6 +32,7 @@ import { BackgroundTaskManager } from '@/services/backgroundTaskManager';
 import { fetchChallenges } from '@/store/challengesSlice';
 import AsyncStorage from '@/utils/kvStore';
 import { Provider } from 'react-redux';
+import { MembershipModalProvider } from '@/contexts/MembershipModalContext';
 
 
 function Bootstrapper({ children }: { children: React.ReactNode }) {
@@ -207,12 +208,14 @@ function Bootstrapper({ children }: { children: React.ReactNode }) {
 
   return (
     <DialogProvider>
-      {children}
-      <PrivacyConsentModal
-        visible={showPrivacyModal}
-        onAgree={handlePrivacyAgree}
-        onDisagree={handlePrivacyDisagree}
-      />
+      <MembershipModalProvider>
+        {children}
+        <PrivacyConsentModal
+          visible={showPrivacyModal}
+          onAgree={handlePrivacyAgree}
+          onDisagree={handlePrivacyDisagree}
+        />
+      </MembershipModalProvider>
     </DialogProvider>
   );
 }