feat(app): initialize uni-app with routing, stores, and infrastructure

- Vue 3 + TypeScript + Pinia + SCSS
- 3-tab navigation (home, booking, profile) + 11 sub-pages
- HTTP client with JWT auth, request interceptors
- Pinia stores: user (auth, profile, memberships), studio, booking
- Utility functions: price formatting, date helpers
- WeChat login helper
- All pages as stubs ready for implementation

packages/app/src/pages/profile/index.vue

@@ -0,0 +1,23 @@
+<template>
+  <view class="profile-page">
+    <view class="placeholder">
+      <text>我的 - 待实现</text>
+    </view>
+  </view>
+</template>
+
+<script setup lang="ts">
+</script>
+
+<style lang="scss" scoped>
+.profile-page {
+  min-height: 100vh;
+}
+.placeholder {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  height: 400rpx;
+  color: #999;
+}
+</style>