Complexity reduction, measured

Measure cognitive complexity and duplicate code with PMD (Java) or rust-code-analysis-cli (Rust), then reduce both by pure-move extraction, re-measuring after every step. Runs over a subsystem or over a PR diff. Use this when the user asks to simplify, refactor, clean up, or reduce the complexity of a subsystem, asks "how complex is X", asks to find duplicate code, asks to make code "beautiful", or asks for a complexity check on a diff or PR. It measures before it edits and re-measures after; it never accepts an unmeasured claim that a change helped. It reports only, unless the user passes `--refactor`. It is not `/simplify`, which reads the current diff and has no m…