Git diff summariser

When to use

The user pastes or points at a git diff and wants a summary rather than reading it line-by-line.

Examples:

• "Summarise this diff"
• "Draft a commit message for these changes"
• "What changed in this PR?"

Steps

1. Get the diff content. Either the user pasted it, or they point at a file — use fs_read on a .diff / .patch file. If you have sandbox access and a git repo cloned in /workspace, the shell script below can regenerate the diff.