Review changed code for reuse, quality, and efficiency, then clean up what you find — duplicated logic that could reuse an existing helper, hacky or redundant patterns, needless work on hot paths. Quality cleanup only: not bugs (that's code-review) and not behavior-preserving restructuring on request (that's refactor). Use when the user says "simplify", "clean this up", "is there a simpler way", or "tidy the diff".
