feat(wish-tree): 许愿树页面微调七项

1. 背景图 aspectFill 撑满全屏，挂载点坐标按裁剪比例重算，便签不再落在图外
2. 写下心愿按钮单行不换行，缩小尺寸
3. 移除页面内许愿树标题/数量/最近心愿，点击便签弹出便签式详情卡
4. 默认请求100条：最新50条挂树，其余以弹幕形式缓缓飘过
5. MAKE A WISH 下方增加顶级位置轮播（购买后24小时内展示），点击弹出金色便签详情，与普通便签区分
6. 多棵树分屏轮播（swiper），背景图从服务器获取，带指示点
7. 后端：WishTree新增image字段，Wish新增isTop运行时标记，图片用go:embed内嵌随二进制部署，/images路由提供访问

mini/pages/wish-tree/wish-tree.wxml

@@ -1,94 +1,117 @@
 <view class="container">
   <!-- 背景氛围：萤火虫 -->
-  <view class="ambiance">
-    <view 
-      wx:for="{{fireflies}}" 
-      wx:key="index"
-      class="firefly"
-      style="left: {{item.left}}%; top: {{item.top}}%; width: {{item.size}}px; height: {{item.size}}px; animation-duration: {{item.duration}}s; animation-delay: {{item.delay}}s;"
-    ></view>
-  </view>
+  <view class="firefly" 
+    wx:for="{{fireflies}}" 
+    wx:key="index"
+    style="left: {{item.left}}%; top: {{item.top}}%; width: {{item.size}}px; height: {{item.size}}px; animation-duration: {{item.duration}}s; animation-delay: {{item.delay}}s;"
+  ></view>
 
-  <!-- 背景氛围：花瓣 -->
-  <view class="petals">
-    <view 
-      wx:for="{{petals}}" 
-      wx:key="index"
-      class="petal"
-      style="left: {{item.left}}%; width: {{item.size}}px; height: {{item.size}}px; animation-duration: {{item.duration}}s; animation-delay: {{item.delay}}s;"
-    ></view>
-  </view>
+  <!-- 多树分屏轮播 -->
+  <swiper 
+    class="tree-swiper" 
+    current="{{currentTreeIndex}}" 
+    bindchange="onSwiperChange"
+    circular="{{trees.length > 1}}"
+  >
+    <swiper-item wx:for="{{trees}}" wx:key="id">
+      <view class="tree-page">
+        <!-- 背景图撑满全屏 -->
+        <image 
+          src="{{item.imageUrl}}" 
+          class="tree-bg"
+          mode="aspectFill"
+        />
 
-  <!-- 边缘暗角，让树从中心发光 -->
-  <view class="vignette"></view>
-
-  <!-- 主内容 -->
-  <view class="main-content">
-    <!-- 头部 -->
-    <view class="header">
-      <text class="subtitle">MAKE A WISH</text>
-      <text class="title">许愿树</text>
-      <text class="description">月色微凉，灯火摇曳。写下心中所愿，挂上枝头，静待花开成真。</text>
-      <text class="wish-count">已有 <text class="count">{{wishes.length}}</text> 个心愿挂满枝头</text>
-    </view>
-
-    <!-- 许愿树 -->
-    <view class="tree-container">
-      <image 
-        src="/images/wish-tree.jpg" 
-        class="tree-image"
-        mode="aspectFit"
-      />
-      
-      <!-- 许愿标签 -->
-      <view 
-        wx:for="{{wishes}}" 
-        wx:key="id"
-        class="wish-tag {{item.isNew ? 'new' : ''}}"
-        style="left: {{item.x}}%; top: {{item.y}}%;"
-        bindtap="viewWishDetail"
-        data-id="{{item.id}}"
-      >
-        <view class="tag-sway" style="animation-duration: {{item.swayDuration}}s; animation-delay: {{item.swayDelay}}s;">
-          <!-- 挂绳 -->
-          <view class="tag-string" style="background: linear-gradient(to bottom, transparent, {{item.color}});"></view>
-          <!-- 绳结 -->
-          <view class="tag-knot" style="background: {{item.color}}; box-shadow: 0 0 8px {{item.color}};"></view>
-          <!-- 标签 -->
-          <view class="tag-content" style="background: {{item.bgColor}}; border: 1px solid {{item.borderColor}}; box-shadow: 0 4px 16px {{item.shadowColor}};">
-            <text class="tag-text">{{item.content}}</text>
-            <text class="tag-author">—— {{item.author}}</text>
+        <!-- 树上的许愿便签（最新50条） -->
+        <view 
+          wx:for="{{item.hangWishes}}" 
+          wx:for-item="wish" 
+          wx:key="id"
+          class="wish-tag {{wish.isNew ? 'new' : ''}}"
+          style="left: {{wish.x}}%; top: {{wish.y}}%;"
+          catchtap="openDetail"
+          data-wish="{{wish}}"
+        >
+          <view class="tag-sway" style="animation-duration: {{wish.swayDuration}}s; animation-delay: {{wish.swayDelay}}s;">
+            <view class="tag-string" style="background: linear-gradient(to bottom, transparent, {{wish.color}});"></view>
+            <view class="tag-knot" style="background: {{wish.color}}; box-shadow: 0 0 8rpx {{wish.color}};"></view>
+            <view class="tag-content" style="background: {{wish.bgColor}}; border: 1rpx solid {{wish.borderColor}}; box-shadow: 0 6rpx 20rpx {{wish.shadowColor}};">
+              <text class="tag-text">{{wish.content}}</text>
+              <text class="tag-author">—— {{wish.author}}</text>
+            </view>
           </view>
         </view>
       </view>
-    </view>
+    </swiper-item>
+  </swiper>
 
-    <!-- 最近的心愿 -->
-    <view class="recent-section">
-      <text class="section-title">最 近 的 心 愿</text>
-      <scroll-view class="recent-list" scroll-x enhanced show-scrollbar="{{false}}">
-        <view 
-          wx:for="{{recentWishes}}" 
-          wx:key="id"
-          class="recent-item"
-          bindtap="viewWishDetail"
-          data-id="{{item.id}}"
-        >
-          <text class="recent-text">{{item.content}}</text>
-          <text class="recent-author">—— {{item.author}}</text>
-        </view>
-      </scroll-view>
-    </view>
+  <!-- 弹幕层（超出50条的心愿缓缓飘过） -->
+  <view class="danmaku-layer">
+    <view 
+      wx:for="{{currentDanmaku}}" 
+      wx:key="id"
+      class="danmaku-item {{item.type === 'paid' ? 'paid' : ''}}"
+      style="top: {{item.top}}%; animation-duration: {{item.duration}}s; animation-delay: {{item.delay}}s;"
+    >{{item.content}} · {{item.author}}</view>
   </view>
 
-  <!-- 许愿按钮 -->
+  <!-- 边缘暗角 -->
+  <view class="vignette"></view>
+
+  <!-- 顶部：MAKE A WISH + 顶级位置轮播 -->
+  <view class="header">
+    <text class="subtitle">MAKE A WISH</text>
+    <swiper 
+      wx:if="{{topWishes.length > 0}}" 
+      class="top-swiper" 
+      vertical 
+      autoplay 
+      circular 
+      interval="3000"
+      duration="500"
+    >
+      <swiper-item wx:for="{{topWishes}}" wx:key="id">
+        <view class="top-item" catchtap="openDetail" data-wish="{{item}}">
+          <text class="top-crown">👑</text>
+          <text class="top-text">{{item.content}}</text>
+          <text class="top-author">—— {{item.author}}</text>
+        </view>
+      </swiper-item>
+    </swiper>
+  </view>
+
+  <!-- 分屏指示点 -->
+  <view class="page-dots" wx:if="{{trees.length > 1}}">
+    <view 
+      wx:for="{{trees}}" 
+      wx:key="id"
+      class="dot {{currentTreeIndex === index ? 'active' : ''}}"
+    ></view>
+  </view>
+
+  <!-- 许愿按钮（树根附近） -->
   <view class="action-bar">
     <button class="btn-wish" bindtap="openCreateModal">
       <text class="icon">🙏</text>
-      <text>写下心愿</text>
+      <text class="btn-text">写下心愿</text>
     </button>
   </view>
 
+  <!-- 便签详情弹窗 -->
+  <view class="detail-modal" wx:if="{{detailWish}}">
+    <view class="detail-mask" bindtap="closeDetail"></view>
+    <view class="note-card {{detailWish.isTop ? 'top-note' : ''}}">
+      <view class="note-string"></view>
+      <view class="note-knot" style="background: {{detailWish.color}};"></view>
+      <view class="note-badge" wx:if="{{detailWish.isTop}}">👑 顶级心愿</view>
+      <text class="note-text">{{detailWish.content}}</text>
+      <view class="note-footer">
+        <text class="note-author">—— {{detailWish.author}}</text>
+        <text class="note-date">{{detailWish.dateStr}}</text>
+      </view>
+    </view>
+  </view>
+
   <!-- 许愿弹窗 -->
   <view class="modal" wx:if="{{showCreateModal}}">
     <view class="modal-mask" bindtap="closeCreateModal"></view>
@@ -133,7 +156,7 @@
 
         <!-- 付费商品选择 -->
         <view class="product-section" wx:if="{{wishType === 'paid'}}">
-          <view class="section-title">选择许愿商品</view>
+          <view class="product-title">选择许愿商品</view>
           <view class="product-list">
             <view 
               wx:for="{{products}}"