约束概述
理解工作流的确定性与活动的幂等性，以及它们各自的执行边界。
Idempotent vs. deterministic
In Durable Workflow 2.0, determinism keeps orchestration replay-safe while idempotency makes retried activity effects safe.
执行保证与幂等性
v2 关于重放、重试、租约过期、重新投递和默认幂等标识的公开契约。
工作流约束
保持重放的确定性，并在应用启动时发现不安全的调用。
活动约束
让外部副作用能够安全应对重试、租约过期和重新投递。
Constraints Summary
What workflow and activity code may do.
Structural Limits
Structural limits cap the resource consumption of a single workflow run. When an operation would exceed a configured limit, the engine records a typed failure with a machine-readable structural_limit failure category and the specific limit kind, then fails the run. This protects the system from unbounded fan-out, oversized payloads, and metadata bloat.