feat: 排行榜虚拟领奖台 + 勋章对齐与尺寸统一

- 领奖台数据不足 3 名时显示虚拟空位(虚线轮廓+虚位以待)
- 领奖台勋章与昵称对齐改为等高盒结构性修复(移除 margin 盲推)
- 全 app 成就勋章图标尺寸统一为 30rpx(前三名/列表/设置页/记录页一致)
- 勋章 SVG 按包围盒精确居中(utils/icons.js)
- 设置页/记录页勋章展示配套调整

pages/timer/timer.js

@@ -56,6 +56,9 @@ Page({
     completionStreak: 0,
     completionLevel: 'normal',
     completionMessage: '',
+    // 完成弹窗科学提示（config.scienceTips 按本次时长选段）
+    completionTipValue: '',
+    completionTipRisk: '',
     icons: iconsMod.build()
   },
 
@@ -700,6 +703,22 @@ Page({
     this._saveAndShowCompletion(elapsed)
   },
 
+  /**
+   * 按本次实际训练时长从 config.scienceTips 选一段提示。
+   * 命中第一条 maxSeconds 大于 elapsed 的配置；缺失配置时返回空（不显示）。
+   */
+  _pickScienceTip(elapsed) {
+    const tips = config.scienceTips || []
+    const sec = Math.max(0, Number(elapsed) || 0)
+    for (const t of tips) {
+      const max = t && t.maxSeconds == null ? Infinity : (t && t.maxSeconds)
+      if (sec < max) {
+        return { value: (t && t.value) || '', risk: (t && t.risk) || '' }
+      }
+    }
+    return { value: '', risk: '' }
+  },
+
   /**
    * Persist the just-finished training and pop the big completion modal.
    * Called from finishTraining (the user manually ends; the timer keeps
@@ -743,6 +762,7 @@ Page({
     try { wx.setStorageSync('_lb_force_refresh', true) } catch (e) {}
 
     const finalStreak = storage.getStreak().count
+    const scienceTip = this._pickScienceTip(elapsed)
 
     this.setData({
       // Background effects keep playing behind the modal
@@ -761,7 +781,10 @@ Page({
       completionOvertime: this.data.isCircuitMode ? 0 : Math.max(0, elapsed - this.data.duration),
       completionStreak: finalStreak,
       completionLevel: level,
-      completionMessage: message
+      completionMessage: message,
+      // 科学提示（按时长分段；无配置时为空字符串，wx:if 不渲染）
+      completionTipValue: scienceTip.value,
+      completionTipRisk: scienceTip.risk
     })
 
     // Animate the big number from 0 to elapsed