Show HN: Zsh helpers for LLM Git diff review

= Pipe any Git diff range into Claude Code CLI =

Review the last commit of your feature branch:

  claudiff "HEAD^..HEAD" "code review"

Review the last 3 commits of your feature branch:

  claudiff "HEAD~3..HEAD" "produce gherkin acceptance criteria"

Review working tree changes (uncommitted):

  claudiff HEAD "Suggest code cleanups"

Review staged changes:

  claudiff --staged "review as if you were Linus Torvalds"

Review a pull request branch before merging:

  claudiff "origin/main..HEAD" "review as if you were Anders Hejlsberg"

Since last tag:

  claudiff "$(git describe --tags --abbrev=0)..HEAD" "Generate release notes"

Or do the same as above with Github Copilot CLI using `copdiff` instead of `claudiff`