fix: 修复 Vue 模板 data-* 属性绑定语法错误

- 将 data-nutrient-index/data-item-id/data-item-kid 的 {{ }} 插值语法
  改为 v-bind (:) 简写语法
- 适配 Vue 2 模板编译规范

Error: Interpolation inside attributes has been removed.
Use v-bind or the colon shorthand instead.

msh_single_uniapp/pages/tool/nutrition-knowledge.vue

@@ -36,7 +36,7 @@
 						class="nutrient-card" 
 						v-for="(item, index) in nutrientList" 
 						:key="index"
-						@click="goToNutrientDetail" data-nutrient-index="{{ index }}"
+						@click="goToNutrientDetail" :data-nutrient-index="index"
 					>
 						<view class="nutrient-icon-wrapper">
 							<text class="nutrient-icon">{{ item.icon }}</text>
@@ -65,7 +65,7 @@
 						class="knowledge-item" 
 						v-for="(item, index) in (guideList || [])" 
 						:key="item.knowledgeId || item.id || index"
-						@click="goToDetail" data-item-id="{{ item.id }}" data-item-kid="{{ item.knowledgeId }}"
+						@click="goToDetail" :data-item-id="item.id" :data-item-kid="item.knowledgeId"
 					>
 						<view class="knowledge-cover" v-if="item.coverImage || item.cover_image">
 							<image :src="item.coverImage || item.cover_image" mode="aspectFill" class="cover-img" />
@@ -96,7 +96,7 @@
 						class="knowledge-item" 
 						v-for="(item, index) in (articleList || [])" 
 						:key="item.knowledgeId || item.id || index"
-						@click="goToDetail" data-item-id="{{ item.id }}" data-item-kid="{{ item.knowledgeId }}"
+						@click="goToDetail" :data-item-id="item.id" :data-item-kid="item.knowledgeId"
 					>
 						<view class="knowledge-cover" v-if="item.coverImage || item.cover_image">
 							<image :src="item.coverImage || item.cover_image" mode="aspectFill" class="cover-img" />