feat(db): add User and Session models

backend/src/cyclone/db.py

@@ -30,6 +30,7 @@ from sqlalchemy import (
     Numeric,
     String,
     Text,
+    func,
     text,
 )
 from sqlalchemy.orm import DeclarativeBase, Mapped, mapped_column, relationship, sessionmaker
@@ -836,3 +837,27 @@ class ClearhouseORM(Base):
     filename_block_json: Mapped[dict] = mapped_column(JSONText, nullable=False)
     sftp_block_json: Mapped[dict] = mapped_column(JSONText, nullable=False)
     updated_at: Mapped[str] = mapped_column(String(32), nullable=False)
+
+
+class User(Base):
+    """Auth user (admin / user / viewer)."""
+
+    __tablename__ = "users"
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True)
+    username: Mapped[str] = mapped_column(String(64), unique=True, index=True)
+    password_hash: Mapped[str] = mapped_column(String(255), nullable=False)
+    role: Mapped[str] = mapped_column(String(16), nullable=False)
+    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), server_default=func.now())
+    disabled_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
+
+
+class Session(Base):
+    """Server-side auth session (HttpOnly cookie holds the id)."""
+
+    __tablename__ = "sessions"
+
+    id: Mapped[str] = mapped_column(String(64), primary_key=True)
+    user_id: Mapped[int] = mapped_column(ForeignKey("users.id"), index=True)
+    expires_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), index=True)
+    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), server_default=func.now())