feat: init fitness-coach (backend + miniprogram)

- backend: NestJS service with exercise/plan data
- miniprogram: WeChat mini program client
- exclude node_modules, dist, runtime data-store, local env

miniprogram/app.js

@@ -0,0 +1,26 @@
+const { BASE_URL } = require('./config');
+
+App({
+  globalData: {
+    // 状态栏高度（px），由 onLaunch 读取，供自定义导航栏计算顶部留白
+    statusBarHeight: 20,
+    // 后端基础地址
+    baseUrl: BASE_URL
+  },
+
+  onLaunch() {
+    // 读取窗口信息以获取状态栏高度（兼容新旧 API）
+    try {
+      const info = (typeof wx.getWindowInfo === 'function')
+        ? wx.getWindowInfo()
+        : wx.getSystemInfoSync();
+      this.globalData.statusBarHeight = info.statusBarHeight || 20;
+    } catch (e) {
+      this.globalData.statusBarHeight = 20;
+    }
+
+    // 可选：静默登录（占位，不请求真实后端）
+    // const { getOpenid } = require('./utils/auth');
+    // getOpenid();
+  }
+});