fix: 修复6项测试问题并补全配套资源

- 修复油脂类食物推荐量系数 (5.7→2.5) [ToolCalculatorServiceImpl]
- AI营养师接入真实Coze API，替换Mock回复 [ToolAiNutritionistServiceImpl]
- 食物百科详情新增钙/铁/维C/嘌呤/重量基准字段返回 [ToolFoodServiceImpl]
- V2Food模型新增purine、servingSize字段 [V2Food.java]
- 食物百科详情页动态重量标注+新增4项营养展示+替换Figma URL [food-detail.vue]
- 修复营养素列表dataset传参Bug(WeChat camelCase) [nutrition-knowledge.vue]
- 营养素详情页接入后端API+兜底本地数据+替换Figma URL [nutrient-detail.vue]
- 新增数据库迁移脚本及参考初始化数据 [docs/sql/]
- 新增前端占位图标5个 [static/images/]
- 新增开发任务完成报告 [docs/]

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

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(index)"
 					>
 						<view class="nutrient-icon-wrapper">
 							<text class="nutrient-icon">{{ item.icon }}</text>
@@ -290,8 +290,7 @@ export default {
 			this.currentTab = tab;
 			await this.loadKnowledgeList();
 		},
-		goToNutrientDetail(event) {
-			const index = event.currentTarget.dataset.nutrientIndex;
+		goToNutrientDetail(index) {
 			const item = this.nutrientList[index];
 			if (!item) return;
 			uni.navigateTo({