Git diff stat commands now end options with --

What

Claude Code runs git to count changed lines. Its git diff --shortstat and --numstat -z calls now end their arguments with --. In git, -- marks the end of options. Before, nothing followed the ref argument.

Why

A branch or ref name that starts with a dash, or looks like a file path, can no longer be read as an option or confused with a path. This is a small hardening against option injection through ref names.