Simplify: Code Review and Cleanup

Review all changed files for reuse, quality, and efficiency. Fix any issues found.

Phase 1: Identify Changes

Run git diff, or git diff HEAD if there are staged changes. If there are no git changes, review the most recently modified files that the user mentioned or that were edited earlier in the conversation.

Phase 2: Review in Three Passes

If the active Codex instructions allow subagents, launch three review agents in parallel and pass each one the full diff. If subagents are unavailable or not allowed, perform the same three passes locally.

Pass 1: Code Reuse Review

For each change:

1. Search for existing utilities and helpers that could replace newly written code. Look for similar patterns elsewhere in the codebase. Common locations are utility directories, shared modules, and files adjacent to the changed ones.
2. Flag any new function that duplicates existing functionality. Suggest the existing function to use instead.
3. Flag any inline logic that could use an existing utility, such as hand-rolled string manipulation, manual path handling, custom environment checks, ad-hoc type guards, and similar patterns.