gh-contribute — Clean PRs to Upstream Repos

Turn local changes into a clean, professional pull request against an upstream repo you don't own. Handles the full fork → branch → commit → push → PR pipeline, and splits work into multiple PRs when the changes span unrelated concerns.

When to Use

• User wants to contribute to an open-source project they don't have write access to
• User already has local edits and needs them shipped as a PR upstream
• User asks to "fork this repo and send a PR"
• User has mixed changes (e.g. docs + feature + refactor) and wants them split properly

Non-Goals

• Does not write code changes — assumes the user (or a prior step) already has the desired modifications in the working tree or in their head
• Does not review the project's own PRs (see gh-tidy)
• Does not mirror to GitLab/Gitea — GitHub only