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>

docs/sql/migration_2026-03-25_add_food_fields.sql

@@ -0,0 +1,49 @@
+-- ============================================================
+-- 数据库迁移脚本
+-- 版本: v1.0
+-- 日期: 2026-03-25
+-- 描述: 为 v2_food 表新增嘌呤含量和重量基准字段
+-- ============================================================
+
+-- 1. 新增 purine 字段（嘌呤含量，单位 mg）
+ALTER TABLE v2_food
+    ADD COLUMN purine DECIMAL(10, 2) DEFAULT NULL COMMENT '嘌呤含量(mg)';
+
+-- 2. 新增 serving_size 字段（营养成分对应重量基准）
+ALTER TABLE v2_food
+    ADD COLUMN serving_size VARCHAR(50) DEFAULT '每100g' COMMENT '营养成分对应的食物重量基准，如"每100g"、"每份(50g)"';
+
+-- 验证
+DESC v2_food;
+
+-- ============================================================
+-- 参考数据初始化示例（按需执行）
+-- 数据来源: https://www.ishen365.com/article/cereal
+-- ============================================================
+
+-- 谷薯类
+UPDATE v2_food SET calcium = 13,  iron = 2.3, vitamin_c = 0,  purine = 18.4, serving_size = '每100g' WHERE name = '大米'   AND category_name LIKE '%谷%';
+UPDATE v2_food SET calcium = 34,  iron = 5.1, vitamin_c = 0,  purine = 25.0, serving_size = '每100g' WHERE name = '小米'   AND category_name LIKE '%谷%';
+UPDATE v2_food SET calcium = 38,  iron = 5.9, vitamin_c = 0,  purine = 22.4, serving_size = '每100g' WHERE name = '玉米'   AND category_name LIKE '%谷%';
+UPDATE v2_food SET calcium = 31,  iron = 3.5, vitamin_c = 0,  purine = 17.1, serving_size = '每100g' WHERE name = '面粉'   AND category_name LIKE '%谷%';
+
+-- 蔬菜类
+UPDATE v2_food SET calcium = 48,  iron = 1.2, vitamin_c = 14, purine = 10.1, serving_size = '每100g' WHERE name = '菠菜'   AND category_name LIKE '%蔬%';
+UPDATE v2_food SET calcium = 36,  iron = 0.5, vitamin_c = 4,  purine = 5.5,  serving_size = '每100g' WHERE name = '西红柿' AND category_name LIKE '%蔬%';
+UPDATE v2_food SET calcium = 21,  iron = 0.3, vitamin_c = 2,  purine = 3.4,  serving_size = '每100g' WHERE name = '土豆'   AND category_name LIKE '%蔬%';
+
+-- 水果类
+UPDATE v2_food SET calcium = 4,   iron = 0.6, vitamin_c = 8,  purine = 0.9,  serving_size = '每100g' WHERE name = '苹果'   AND category_name LIKE '%水果%';
+UPDATE v2_food SET calcium = 7,   iron = 0.2, vitamin_c = 8,  purine = 1.9,  serving_size = '每100g' WHERE name = '香蕉'   AND category_name LIKE '%水果%';
+
+-- 肉蛋类
+UPDATE v2_food SET calcium = 11,  iron = 2.5, vitamin_c = 0,  purine = 122.5, serving_size = '每100g' WHERE name = '猪肉' AND category_name LIKE '%肉%';
+UPDATE v2_food SET calcium = 9,   iron = 2.3, vitamin_c = 0,  purine = 107.6, serving_size = '每100g' WHERE name = '牛肉' AND category_name LIKE '%肉%';
+UPDATE v2_food SET calcium = 56,  iron = 2.0, vitamin_c = 0,  purine = 2.6,   serving_size = '每100g' WHERE name = '鸡蛋' AND category_name LIKE '%蛋%';
+
+-- 豆类
+UPDATE v2_food SET calcium = 191, iron = 8.2, vitamin_c = 0,  purine = 166.5, serving_size = '每100g' WHERE name = '黄豆' AND category_name LIKE '%豆%';
+UPDATE v2_food SET calcium = 164, iron = 6.4, vitamin_c = 0,  purine = 116.9, serving_size = '每100g' WHERE name = '豆腐' AND category_name LIKE '%豆%';
+
+-- 将所有未设置 serving_size 的记录默认填充
+UPDATE v2_food SET serving_size = '每100g' WHERE serving_size IS NULL OR serving_size = '';