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/components/exercise-card/index.wxml

@@ -0,0 +1,21 @@
+<view class="ex-card {{compact ? 'ex-card--compact' : ''}}" bindtap="onTap">
+  <view class="ex-card__media">
+    <image
+      wx:if="{{exercise.gifUrl || exercise.image}}"
+      class="ex-card__img"
+      src="{{exercise.gifUrl || exercise.image}}"
+      mode="aspectFill"
+      lazy-load="true" />
+    <view wx:else class="ex-card__ph">🏋️</view>
+    <view wx:if="{{exercise.typeLabel}}" class="ex-card__type">{{exercise.typeLabel}}</view>
+    <view wx:if="{{score > 0}}" class="ex-card__score">匹配 {{score}}</view>
+  </view>
+  <view class="ex-card__body">
+    <view class="ex-card__name">{{exercise.name}}</view>
+    <view class="ex-card__chips">
+      <text wx:if="{{exercise.targetLabel}}" class="tag tag--gold">{{exercise.targetLabel}}</text>
+      <text wx:if="{{exercise.equipmentLabel}}" class="tag">{{exercise.equipmentLabel}}</text>
+    </view>
+    <view wx:if="{{reason}}" class="ex-card__reason">{{reason}}</view>
+  </view>
+</view>