first commit 稳定版本，已知该版本存在问题，前端未对数据进行校验，没有集成导出excel

services/report_service.py

@@ -0,0 +1,19 @@
+import os
+from services.nutrition_service import NutritionService
+from pdf_builder import NutritionPDFBuilder
+
+
+class NutritionReportService:
+    def __init__(self):
+        base_dir = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+
+        food_db_path = os.path.join(base_dir, "food_db.json")
+        config_path = os.path.join(base_dir, "config", "nutrition_template.json")
+
+        self.nutrition_service = NutritionService(food_db_path, config_path)
+        self.pdf_builder = NutritionPDFBuilder()
+
+    def generate_report_from_json(self, front_json, output_path):
+        report_data = self.nutrition_service.build_report_data(front_json)
+        self.pdf_builder.build(report_data, output_path)
+        return report_data