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/index/index.wxml

@@ -0,0 +1,99 @@
+<view class="home" style="padding-top: {{statusBarHeight}}px;">
+  <!-- Hero -->
+  <view class="hero">
+    <view class="hero__eyebrow">FITCOACH · 智能健身教练</view>
+    <view class="hero__title">今天，练点什么？</view>
+    <view class="hero__sub">精准匹配你的目标肌群，让每一次训练都更高效</view>
+
+    <view class="search-pill" bindtap="onSearch">
+      <text class="search-pill__icon">🔍</text>
+      <text class="search-pill__ph">搜索动作 / 器械 / 部位</text>
+    </view>
+
+    <view class="cta" bindtap="goRecommend">
+      <text class="cta__icon">✨</text>
+      <text class="cta__txt">智能推荐</text>
+      <text class="cta__arrow">›</text>
+    </view>
+  </view>
+
+  <!-- 快捷入口 2x3 -->
+  <view class="section quick">
+    <view class="quick__grid">
+      <view
+        wx:for="{{quickEntries}}"
+        wx:key="key"
+        class="quick__tile"
+        data-url="{{item.url}}"
+        bindtap="onQuick">
+        <text class="quick__emoji">{{item.emoji}}</text>
+        <text class="quick__label">{{item.label}}</text>
+      </view>
+    </view>
+  </view>
+
+  <!-- 精选动作 横向滑动 -->
+  <view class="section">
+    <section-header eyebrow="FEATURED" title="精选动作" subtitle="编辑精选 · 高效入门" action="全部" bind:action="goRecommend" />
+    <scroll-view wx:if="{{featured.length}}" scroll-x class="hscroll">
+      <view class="hscroll__item" wx:for="{{featured}}" wx:key="id">
+        <exercise-card exercise="{{item}}" compact bind:tap="onExercise" />
+      </view>
+    </scroll-view>
+    <view wx:else class="empty">暂无数据</view>
+  </view>
+
+  <!-- 训练组合 横向 -->
+  <view class="section" wx:if="{{collections.length}}">
+    <section-header eyebrow="PROGRAMS" title="训练组合" subtitle="一键开启主题训练" />
+    <scroll-view scroll-x class="chip-scroll">
+      <view
+        wx:for="{{collections}}"
+        wx:key="slug"
+        class="prog"
+        style="background: {{item.color}}22; border-color: {{item.color}}55;"
+        data-slug="{{item.slug}}"
+        bindtap="onCollection">
+        <text class="prog__emoji">{{item.emoji}}</text>
+        <text class="prog__name" style="color: {{item.color}};">{{item.name}}</text>
+      </view>
+    </scroll-view>
+  </view>
+
+  <!-- 按部位浏览 -->
+  <view class="section">
+    <section-header eyebrow="BY BODY PART" title="按部位浏览" subtitle="选择你的目标区域" />
+    <view class="bp-grid">
+      <view
+        wx:for="{{bodyParts}}"
+        wx:key="value"
+        class="bp"
+        data-value="{{item.value}}"
+        data-label="{{item.label}}"
+        bindtap="onScanBodyPart">
+        <text class="bp__label">{{item.label}}</text>
+        <text class="bp__count">{{item.count}} 个动作</text>
+      </view>
+    </view>
+  </view>
+
+  <!-- 热门器械 -->
+  <view class="section" wx:if="{{equipment.length}}">
+    <section-header eyebrow="EQUIPMENT" title="热门器械" subtitle="按器械筛选动作" />
+    <scroll-view scroll-x class="chip-scroll">
+      <view
+        wx:for="{{equipment}}"
+        wx:key="value"
+        class="eq"
+        data-value="{{item.value}}"
+        data-label="{{item.label}}"
+        bindtap="onScanEquipment">
+        <text class="eq__name">{{item.label}}</text>
+        <text class="eq__count">{{item.count}}</text>
+      </view>
+    </scroll-view>
+  </view>
+
+  <view style="height: 160rpx;"></view>
+  <bottom-nav active="home" />
+</view>