Add 卓米会 mini program and admin server.

Initial commit of the WeChat mini program, Express backend, and admin console.

Co-authored-by: Cursor <cursoragent@cursor.com>

miniprogram/components/activity-board/index.wxml

@@ -0,0 +1,48 @@
+<view class="board" wx:if="{{activity}}">
+  <view class="banner">
+    <video
+      wx:if="{{video}}"
+      class="banner-media"
+      src="{{video}}"
+      controls
+      show-center-play-btn
+      object-fit="cover"
+      poster="{{poster}}"
+    />
+    <block wx:else>
+      <image wx:if="{{poster}}" class="banner-media" src="{{poster}}" mode="aspectFill" />
+      <view class="banner-shade"></view>
+      <text class="banner-title">{{activity.title}}</text>
+    </block>
+    <view class="badge" wx:if="{{activity.isCurrent}}">当前活动</view>
+  </view>
+
+  <view class="card">
+    <text class="brand">{{activity.brandName}}</text>
+    <text wx:if="{{activity.brandDesc}}" class="desc">{{activity.brandDesc}}</text>
+  </view>
+
+  <view class="card info">
+    <view class="row">
+      <text class="label">活动名称</text>
+      <text class="value">{{activity.title}}</text>
+    </view>
+    <view class="row">
+      <text class="label">活动时间</text>
+      <text class="value">{{activity.startAt || '待定'}}</text>
+    </view>
+    <view class="row last">
+      <text class="label">会场地址</text>
+      <text class="value">{{activity.address || '待定'}}</text>
+    </view>
+  </view>
+
+  <view class="btn green" hover-class="btn-pressed" bindtap="onMap">📍 一键导航</view>
+  <view
+    class="btn teal {{ended ? 'disabled' : ''}}"
+    hover-class="{{ended ? 'none' : 'btn-pressed'}}"
+    bindtap="onSignup"
+  >{{ended ? '活动已结束' : '立即报名'}}</view>
+
+  <view wx:if="{{showPast}}" class="more" bindtap="onPast">查看往期活动 ›</view>
+</view>