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/pages/collection/collection.wxml

@@ -0,0 +1,31 @@
+<view class="page">
+  <navbar title="训练计划" />
+  <view class="section" style="padding-top: 8rpx;">
+    <view class="intro">
+      <view class="intro__eyebrow">PROGRAMS</view>
+      <view class="intro__title">挑选你的训练主题</view>
+      <view class="intro__sub">从推、拉、腿到居家无器械，一键开启</view>
+    </view>
+
+    <view class="list" wx:if="{{collections.length}}">
+      <view
+        wx:for="{{collections}}"
+        wx:key="slug"
+        class="col-card"
+        style="background: linear-gradient(135deg, {{item.color}}26, var(--surface)); border-color: {{item.color}}55;"
+        data-slug="{{item.slug}}"
+        bindtap="onOpen">
+        <view class="col-card__emoji" style="background: {{item.color}}22;">{{item.emoji}}</view>
+        <view class="col-card__main">
+          <view class="col-card__name">{{item.name}}</view>
+          <view class="col-card__desc">{{item.description}}</view>
+        </view>
+        <view class="col-card__count" style="color: {{item.color}};">{{counts[item.slug] || ''}} 个动作 ›</view>
+      </view>
+    </view>
+    <view wx:elif="{{!loading}}" class="empty">暂无数据</view>
+    <view wx:else class="empty">加载中…</view>
+  </view>
+  <view style="height: 160rpx;"></view>
+  <bottom-nav active="plan" />
+</view>