feat: 电子药箱小程序 - 4Tab药品管理

- 电子药箱: 药品库存管理 + 手动录入 + 今日用药打卡
- 药品百科: 搜索 + 分类筛选 + 20种药品静态数据
- 惠教中心: 4条药品使用指南课程
- 我的: 家庭成员信息管理
- 自定义TabBar + navigation-bar组件
- SVG药品分类插图

miniprogram/pages/drug-guide/index.wxml

@@ -0,0 +1,63 @@
+<view class="page" wx:if="{{drug.id}}">
+  <navigation-bar title="{{drug.name}}" back="{{true}}" color="white" background="#4A90D9" />
+
+  <view class="drug-header">
+    <image class="header-img" src="{{drugImage}}" mode="aspectFit" />
+    <view class="drug-meta">
+      <view class="meta-item">{{drug.category}}</view>
+      <view class="meta-item">{{drug.form}}</view>
+      <view class="meta-item" wx:if="{{drug.isOTC}}">OTC</view>
+      <view class="meta-item rx" wx:else>Rx</view>
+    </view>
+  </view>
+
+  <view class="section">
+    <view class="section-title">📋 药品简介</view>
+    <view class="section-content">{{drug.description}}</view>
+    <view class="info-row" wx:if="{{drug.manufacturer}}">
+      <view class="info-label">生产厂家</view>
+      <view class="info-value">{{drug.manufacturer}}</view>
+    </view>
+    <view class="info-row" wx:if="{{drug.price}}">
+      <view class="info-label">参考价格</view>
+      <view class="info-value price">{{drug.price}}</view>
+    </view>
+  </view>
+
+  <view class="section">
+    <view class="section-title">💡 用法用量</view>
+    <view class="section-content">{{drug.usage || drug.dosage}}</view>
+  </view>
+
+  <view class="section">
+    <view class="section-title">⏰ 服用时间</view>
+    <view class="section-content">{{drug.timing}}</view>
+  </view>
+
+  <view class="section warning">
+    <view class="section-title">⚠️ 注意事项</view>
+    <view class="section-content">
+      <view wx:for="{{drug.precautions}}" wx:key="index" class="precaution-item">{{index + 1}}. {{item}}</view>
+    </view>
+  </view>
+
+  <view class="section">
+    <view class="section-title">🩺 不良反应</view>
+    <view class="section-content">{{drug.sideEffects}}</view>
+  </view>
+
+  <view class="section tip">
+    <view class="section-title">📌 温馨提示</view>
+    <view class="section-content">{{drug.tip}}</view>
+  </view>
+
+  <view class="disclaimer">本内容仅供参考，具体用药请遵医嘱</view>
+</view>
+
+<view class="page empty-page" wx:else>
+  <navigation-bar title="药品详情" back="{{true}}" color="black" background="#ffffff" />
+  <view class="empty-msg">
+    <view class="empty-icon">🔍</view>
+    <view class="empty-text">未找到药品信息</view>
+  </view>
+</view>