refactor(git): delegate requests_diff_show_raw_shape to requests_raw_diff_shape

Was duplicating requests_raw_diff_shape's Long-flag list verbatim
(minus "patch") instead of delegating and excluding the patch-only
cases. Same list-drift pattern that already caused the git diff -p/
git show -p regression fixed by 7533879 -- delegating rules out the
two lists silently diverging again.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>