Duplication Hunt

What This Skill Does

Scans source code to find duplicated patterns that indicate extraction opportunities. Goes beyond simple copy-paste detection to find three types of duplication:

1. Exact duplicates: Identical code blocks (3+ lines) appearing in two or more locations.
2. Renamed duplicates: Structurally identical code where only variable names, string literals, or numeric constants differ.
3. Structural duplicates: Code blocks that follow the same control flow pattern (same sequence of operations, branches, and loops) with different specifics — the "same shape, different nouns" pattern.

Ranks findings by occurrence count and block size to surface the highest-value extraction candidates first.