Implement user authentication and permissions

app/models/session.py

@@ -0,0 +1,14 @@
+import uuid
+from sqlalchemy import Column, DateTime, ForeignKey, String, Uuid
+
+from app.database import Base
+
+class Session(Base):
+    __tablename__ = "sessions"
+
+    id = Column(Uuid, primary_key=True, default=uuid.uuid4)
+    name = Column(String)
+    refresh_token = Column(String, unique=True, index=True)
+    last_used = Column(DateTime(timezone=True))
+
+    user_id = Column(Uuid, ForeignKey("users.id"), index=True)