Effect v4 review

Review program behavior and the contracts it exposes. Prefer Effect primitives when they remove custom cancellation, scheduling, resource, or coordination logic. Explain the semantic benefit; counting Effect APIs is not a measure of code quality.

Use this skill read-only unless the user also requests fixes. When asked to review or improve this skill itself, inspect its instructions and examples; do not launch a product-code audit.

Default to one reviewer: the current agent, with zero subagents, including whole-repository audits. Follow the delegation and context limits in section 3.

1. Establish scope and ground truth

Read version-grounding.md and the applicable repository instructions before making findings.