Status: IN
The codebase's preference for structural correctness (immutable values, synchronized structures, state ratchets) and its hermetic test design (stdlib-only, injectable time, in-process simulation) reinforce each other — structural invariants reduce the state space to valid subsets, and hermetic modules make those invariants exhaustively testable without non-deterministic infrastructure.
Structural correctness narrows the state space; hermetic testing exploits that narrowing for full coverage
Depends on (SL): correctness-by-construction-not-validation, deterministic-testability-by-design