Refactor: UI & Feature updates (Calculator, UnitConverter, Privacy, Cleanup)

codes/minipro/calculation/miniprogram/pages/history/history.wxml

@@ -0,0 +1,22 @@
+<view class="container">
+  <block wx:if="{{historyList.length > 0}}">
+    <view class="history-list">
+      <view class="history-item" wx:for="{{historyList}}" wx:key="index">
+        <view class="expression">{{item.expression}}</view>
+        <view class="result">= {{item.result}}</view>
+      </view>
+    </view>
+    
+    <view class="footer-btn">
+      <button class="clear-btn" bindtap="clearHistory" hover-class="btn-hover">清空历史记录</button>
+    </view>
+  </block>
+
+  <block wx:else>
+    <view class="empty-state">
+      <text class="empty-icon">📭</text>
+      <text class="empty-text">暂无历史记录</text>
+      <text class="empty-sub">快去使用计算器吧</text>
+    </view>
+  </block>
+</view>