What are the key architectural differences between Catalyst and Restate for building durable agent systems?

Catalyst is built on Dapr Workflows and adds agent runners, workload identity, and MCP tool authorization, enabling a layered architecture where agent orchestration and tool policies are separate. Restate uses a single runtime with virtual objects and journaled execution, simplifying state management but lacking native agent framework integration. Choose Catalyst for modular agent systems with policy controls; choose Restate for simpler, code-first durable services.