refactor: align backend with company-site-member schema and system-level RBAC groups

backend/app/models/user_scope_permission.py

@@ -0,0 +1,24 @@
+from datetime import datetime
+from uuid import uuid4
+
+from sqlalchemy import DateTime, ForeignKey, String, func
+from sqlalchemy.dialects.postgresql import UUID
+from sqlalchemy.orm import Mapped, mapped_column
+
+from app.db.base import Base
+
+
+class UserScopePermission(Base):
+    __tablename__ = "user_scope_permissions"
+
+    id: Mapped[str] = mapped_column(UUID(as_uuid=False), primary_key=True, default=lambda: str(uuid4()))
+    user_id: Mapped[str] = mapped_column(UUID(as_uuid=False), ForeignKey("users.id", ondelete="CASCADE"), nullable=False)
+    module_id: Mapped[str] = mapped_column(UUID(as_uuid=False), ForeignKey("modules.id", ondelete="CASCADE"), nullable=False)
+    action: Mapped[str] = mapped_column(String(32), nullable=False)
+    scope_type: Mapped[str] = mapped_column(String(16), nullable=False)
+    company_id: Mapped[str | None] = mapped_column(UUID(as_uuid=False), ForeignKey("companies.id", ondelete="CASCADE"))
+    site_id: Mapped[str | None] = mapped_column(UUID(as_uuid=False), ForeignKey("sites.id", ondelete="CASCADE"))
+    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), server_default=func.now(), nullable=False)
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), server_default=func.now(), onupdate=func.now(), nullable=False
+    )