Duplication detection
Also called Clone detection
A tool that finds code repeated across a project, usually ignoring names so that a renamed copy still counts. It hands you candidates, and you decide whether they are really the same idea.
A session that doesn't find the helper writes another, and this is the cheap sensor for that. Treat what it finds as questions, since the rule of three says some duplicates are correct.
Say it to your agent
“Run dryer on src/ and show me every pair above 0.82. For each, say whether the two change for the same reason. Merge the ones that do. Leave the ones that don't, and write down why.”