updated the architecture

app/models/user.py

@@ -0,0 +1,25 @@
+import uuid
+from datetime import datetime, timezone
+
+from sqlalchemy import String, DateTime
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+
+from app.database import Base
+
+
+class User(Base):
+    __tablename__ = "users"
+
+    id: Mapped[str] = mapped_column(
+        String(36), primary_key=True, default=lambda: str(uuid.uuid4())
+    )
+    email: Mapped[str] = mapped_column(String(255), unique=True, index=True)
+    username: Mapped[str] = mapped_column(String(100), unique=True, index=True)
+    hashed_password: Mapped[str] = mapped_column(String(255))
+    created_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), default=lambda: datetime.now(timezone.utc)
+    )
+
+    scans = relationship("ScanResult", back_populates="user", lazy="selectin")
+    api_keys = relationship("ApiKey", back_populates="user", lazy="selectin", cascade="all, delete")
+    webhooks = relationship("Webhook", back_populates="user", lazy="selectin", cascade="all, delete")