- add grocery category

- add Dockerfile

backend/models.py

@@ -28,16 +28,28 @@ class Brand(Base):
     # Relationships
     products = relationship("Product", back_populates="brand")
 
+class GroceryCategory(Base):
+    __tablename__ = "grocery_categories"
+    
+    id = Column(Integer, primary_key=True, index=True)
+    name = Column(String, nullable=False, index=True)
+    created_at = Column(DateTime(timezone=True), server_default=func.now())
+    updated_at = Column(DateTime(timezone=True), onupdate=func.now())
+    
+    # Relationships
+    groceries = relationship("Grocery", back_populates="category")
+
 class Grocery(Base):
     __tablename__ = "groceries"
     
     id = Column(Integer, primary_key=True, index=True)
     name = Column(String, nullable=False, index=True)
-    category = Column(String, nullable=False)
+    category_id = Column(Integer, ForeignKey("grocery_categories.id"), nullable=False)
     created_at = Column(DateTime(timezone=True), server_default=func.now())
     updated_at = Column(DateTime(timezone=True), onupdate=func.now())
     
     # Relationships
+    category = relationship("GroceryCategory", back_populates="groceries")
     products = relationship("Product", back_populates="grocery")
 
 class Product(Base):