fix: 修正相對導入，確保 Docker build 正常，USDA API 環境變數說明

init_db.py

@@ -1,12 +1,11 @@
-from database import engine
-from models.nutrition import Base
-from models.meal_log import Base as MealBase
+from database import engine, Base
+from models.nutrition import Nutrition
+from models.meal_log import MealLog
 
 def init_database():
     """Initialize database tables"""
     print("Creating database tables...")
     Base.metadata.create_all(bind=engine)
-    MealBase.metadata.create_all(bind=engine)
     print("Database tables created successfully!")
 
 if __name__ == "__main__":

models/meal_log.py

@@ -1,5 +1,5 @@
 from sqlalchemy import Column, Integer, String, Float, DateTime, JSON
-from ..database import Base
+from database import Base
 
 class MealLog(Base):
     __tablename__ = "meal_logs"

models/nutrition.py

@@ -1,6 +1,6 @@
 # backend/app/models/nutrition.py
 from sqlalchemy import Column, Integer, String, Float, JSON
-from ..database import Base
+from database import Base
 
 class Nutrition(Base):
     __tablename__ = "nutrition"

routers/ai_router.py

@@ -1,8 +1,8 @@
 # 檔案路徑: backend/app/routers/ai_router.py
 
 from fastapi import APIRouter, File, UploadFile, HTTPException
-from ..services.ai_service import classify_food_image  # 直接引入分類函式
-from ..services.nutrition_api_service import fetch_nutrition_data  # 匯入營養查詢函式
+from services.ai_service import classify_food_image  # 直接引入分類函式
+from services.nutrition_api_service import fetch_nutrition_data  # 匯入營養查詢函式
 
 router = APIRouter(
     prefix="/ai",

routers/meal_router.py

@@ -2,8 +2,8 @@ from fastapi import APIRouter, Depends, HTTPException
 from sqlalchemy.orm import Session
 from typing import List, Dict, Any, Optional
 from datetime import datetime
-from ..services.meal_service import MealService
-from ..database import get_db
+from services.meal_service import MealService
+from database import get_db
 from pydantic import BaseModel
 
 router = APIRouter(prefix="/api/meals", tags=["Meals"])

services/meal_service.py

@@ -1,7 +1,7 @@
 from datetime import datetime
 from typing import List, Dict, Any, Optional
 from sqlalchemy.orm import Session
-from ..models.meal_log import MealLog
+from models.meal_log import MealLog
 
 class MealService:
     def __init__(self, db: Session):