- Apply a unified diff patch (`*** Begin Patch`/`*** Update File`/`---`/`+++`/`@@`)
- Uses `git apply` under the hood; tries `-p1` then `-p0`
- Returns an artifact summary and any output from `git apply`

Usage tips:
- Ensure paths in the patch match the project root (prefer `a/` and `b/` prefixes)
- For small edits, consider the Edit or Write tools instead
