Nuevos cambios en el backend

backend/app/models/user.py

@@ -0,0 +1,25 @@
+import uuid
+from datetime import datetime
+
+from sqlalchemy import DateTime, String, func
+from sqlalchemy.dialects.postgresql import UUID
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+
+from app.db.base import Base
+
+
+class User(Base):
+    __tablename__ = "users"
+
+    id: Mapped[uuid.UUID] = mapped_column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
+    email: Mapped[str] = mapped_column(String(255), unique=True, nullable=False, index=True)
+    password_hash: Mapped[str | None] = mapped_column(String(255), nullable=True)
+    google_sub: Mapped[str | None] = mapped_column(String(255), unique=True, nullable=True, index=True)
+    full_name: Mapped[str | None] = mapped_column(String(200), nullable=True)
+    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), server_default=func.now())
+
+    exam_templates: Mapped[list["ExamTemplate"]] = relationship(
+        back_populates="owner",
+        cascade="all, delete-orphan",
+        passive_deletes=True,
+    )