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

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

@@ -33,17 +33,47 @@
                 <view class="arrow-icon">›</view>
             </view>
 
-             <!-- 日期计算 -->
-            <view class="grid-item" bindtap="goToDateCalc" hover-class="grid-item-hover">
-                <view class="icon-box bg-gradient-pink">
-                    <text class="icon">📅</text>
+            <!-- 单位换算 -->
+            <view class="grid-item" bindtap="goToUnitConverter" hover-class="grid-item-hover">
+                <view class="icon-box bg-gradient-green">
+                    <text class="icon">📏</text>
                 </view>
                 <view class="text-box">
-                    <text class="label">日期计算器</text>
-                    <text class="sub-label">日期推算 · 间隔计算 · 农历转换</text>
+                    <text class="label">单位换算</text>
+                    <text class="sub-label">长度 · 重量 · 面积 · 温度</text>
                 </view>
                 <view class="arrow-icon">›</view>
             </view>
+            
+            <!-- 折扣计算 -->
+            <view class="grid-item" bindtap="goToDiscount" hover-class="grid-item-hover">
+                <view class="icon-box bg-gradient-orange">
+                    <text class="icon">🏷️</text>
+                </view>
+                <view class="text-box">
+                    <text class="label">折扣计算</text>
+                    <text class="sub-label">快速计算折后价与节省金额</text>
+                </view>
+                <view class="arrow-icon">›</view>
+            </view>
+        </view>
+
+        <!-- 更多设置 -->
+        <view class="section-title" style="margin-top: 40rpx; display: block;">系统</view>
+        <view class="list-container">
+             <!-- 关于与帮助 -->
+            <view class="list-item" bindtap="goToAbout" hover-class="list-item-hover">
+                <view class="list-icon-box">
+                    <text class="icon-small">ℹ️</text>
+                </view>
+                <text class="list-label">关于与帮助</text>
+                <view class="arrow-icon">›</view>
+            </view>
+        </view>
+
+        <!-- 隐私政策 -->
+        <view class="privacy-link" bindtap="goToPrivacy" style="text-align: center; margin-top: 40rpx; padding-bottom: 20rpx;">
+             <text style="font-size: 24rpx; color: #999;">隐私政策</text>
         </view>
 
         <!-- 推广/banner区域 -->