feat: 支持 nutrition_data_json 嵌套格式存储（带 value/unit）

- 新增 flatToNestedForDb() 方法：将扁平格式转换为带 value/unit 的嵌套格式
- 新增 nestedToFlat() 方法：将嵌套格式转换回扁平格式
- 修改 fillNutrition()：AI 生成的扁平结果转为嵌套格式后存入数据库
- 保持接口返回格式不变（仍为扁平格式）

支持字段映射：
- energyKcal → calories (kcal)
- proteinG → protein (g)
- potassiumMg → potassium (mg)
- phosphorusMg → phosphorus (mg)
- fatG → fat (g)
- carbohydratesG → carbohydrates (g)
- sodiumG → sodium (g)

由 Cursor CLI 实现

msh_crmeb_22/crmeb-service/src/main/java/com/zbkj/service/service/impl/tool/ToolCommunityServiceImpl.java

@@ -614,7 +614,9 @@ public class ToolCommunityServiceImpl implements ToolCommunityService {
         Map<String, Object> nutrition = toolNutritionFillService.fillFromText(text.toString());
         if (nutrition.isEmpty()) throw new CrmebException("AI 未能估算出营养数据");
 
-        post.setNutritionDataJson(JSON.toJSONString(nutrition));
+        // 存库使用嵌套格式（value/unit），与 v2_community_posts.nutrition_data_json 约定一致
+        Map<String, Object> nested = toolNutritionFillService.flatToNestedForDb(nutrition);
+        post.setNutritionDataJson(JSON.toJSONString(nested));
         post.setUpdatedAt(new Date());
         v2CommunityPostDao.updateById(post);
         return nutrition;

msh_crmeb_22/crmeb-service/src/main/java/com/zbkj/service/service/impl/tool/ToolNutritionFillServiceImpl.java

@@ -97,4 +97,53 @@ public class ToolNutritionFillServiceImpl implements ToolNutritionFillService {
         }
         return null;
     }
+
+    @Override
+    public Map<String, Object> flatToNestedForDb(Map<String, Object> flat) {
+        if (flat == null || flat.isEmpty()) return new HashMap<>();
+        Map<String, Object> nested = new HashMap<>();
+        putNested(nested, flat, "energyKcal", "calories", "kcal");
+        putNested(nested, flat, "proteinG", "protein", "g");
+        putNested(nested, flat, "fatG", "fat", "g");
+        putNested(nested, flat, "carbohydratesG", "carbohydrates", "g");
+        putNested(nested, flat, "sodiumG", "sodium", "g");
+        putNested(nested, flat, "potassiumMg", "potassium", "mg");
+        putNested(nested, flat, "phosphorusMg", "phosphorus", "mg");
+        return nested;
+    }
+
+    private void putNested(Map<String, Object> nested, Map<String, Object> flat,
+                          String flatKey, String nestedKey, String unit) {
+        Object v = flat.get(flatKey);
+        if (v == null) return;
+        if (v instanceof Number) {
+            Map<String, Object> entry = new HashMap<>();
+            entry.put("value", ((Number) v).doubleValue());
+            entry.put("unit", unit);
+            nested.put(nestedKey, entry);
+        }
+    }
+
+    @Override
+    @SuppressWarnings("unchecked")
+    public Map<String, Object> nestedToFlat(Map<String, Object> nested) {
+        if (nested == null || nested.isEmpty()) return new HashMap<>();
+        Map<String, Object> flat = new HashMap<>();
+        copyFlat(flat, nested, "calories", "energyKcal");
+        copyFlat(flat, nested, "protein", "proteinG");
+        copyFlat(flat, nested, "fat", "fatG");
+        copyFlat(flat, nested, "carbohydrates", "carbohydratesG");
+        copyFlat(flat, nested, "sodium", "sodiumG");
+        copyFlat(flat, nested, "potassium", "potassiumMg");
+        copyFlat(flat, nested, "phosphorus", "phosphorusMg");
+        return flat;
+    }
+
+    private void copyFlat(Map<String, Object> flat, Map<String, Object> nested,
+                         String nestedKey, String flatKey) {
+        Object entry = nested.get(nestedKey);
+        if (!(entry instanceof Map)) return;
+        Object value = ((Map<?, ?>) entry).get("value");
+        if (value instanceof Number) flat.put(flatKey, ((Number) value).doubleValue());
+    }
 }

msh_crmeb_22/crmeb-service/src/main/java/com/zbkj/service/service/tool/ToolNutritionFillService.java

@@ -11,10 +11,26 @@ import java.util.Map;
 public interface ToolNutritionFillService {
 
     /**
-     * 根据一段饮食/菜品描述文本，调用 AI 估算营养数据并返回结构化结果
+     * 根据一段饮食/菜品描述文本，调用 AI 估算营养数据并返回结构化结果（扁平格式，供 AI/接口使用）
      *
      * @param text 饮食描述（如「今天中午吃了一碗米饭、一份青椒肉丝、一碗紫菜蛋花汤」）
      * @return 包含 energyKcal, proteinG, potassiumMg, phosphorusMg 的 Map，估算不出时为 null
      */
     Map<String, Object> fillFromText(String text);
+
+    /**
+     * 将 AI 返回的扁平格式转为 v2_community_posts.nutrition_data_json 所需的嵌套格式（带 value/unit）
+     *
+     * @param flat 扁平格式，key 为 energyKcal, proteinG, potassiumMg, phosphorusMg 等
+     * @return 嵌套格式，如 {"calories":{"value":1850,"unit":"kcal"},"protein":{"value":65,"unit":"g"},...}
+     */
+    Map<String, Object> flatToNestedForDb(Map<String, Object> flat);
+
+    /**
+     * 将数据库中的嵌套格式（value/unit）转为扁平格式，便于前端或 AI 使用
+     *
+     * @param nested 嵌套格式，如 {"calories":{"value":1850,"unit":"kcal"},...}
+     * @return 扁平格式，如 {"energyKcal":1850,"proteinG":65,...}
+     */
+    Map<String, Object> nestedToFlat(Map<String, Object> nested);
 }