add project structure

app/models.py

@@ -0,0 +1,15 @@
+from datetime import datetime
+
+from sqlalchemy import DateTime, String
+from sqlalchemy.orm import Mapped, mapped_column
+
+from app.db import Base
+
+
+class Box(Base):
+    __tablename__ = "boxes"
+
+    id: Mapped[int] = mapped_column(primary_key=True, index=True)
+    name: Mapped[str] = mapped_column(String(100), nullable=False, default="Sample Box")
+    created_at: Mapped[datetime] = mapped_column(DateTime, default=datetime.utcnow, nullable=False)
+