gh-create-pr

# GitHub PR Creation ## Workflow 1. Read `.github/pull_request_template.md` before drafting the PR body. 2. Collect PR context from the current branch (base/head, scope, linked issues, testing status, breaking changes, release note content). 3. Check if the current branch has been pushed to remote. If not, push it first: - Default remote is `origin`, but ask the user if they want to use a different remote. ```bash git push -u <remote> <head-branch> ``` 4. Determine the base branch: - Inspect the head branch before applying any default. If the head is `release/v<version>`, stop: never open a pull request from a release branch, especially not to `main`. Put an isolated fix on a topic branch and target the release branch, or let Post Release create the metadata sync branch. - Before defaulting an arbitrary topic branch to `main`, inspect its merge base and upstream. A product-code fix that started from `release/v<version>` must stop and be recreated from `main` as a hotfix; only a release-only repair or explicit backport recovery topic may target that exact release branch. - A `backport/v<version>/pr-<number>` head must target the matching `release/v<version>` base and its body must contain `<!-- release-backport-source-pr: <number> -->` on its own line for the exact source hotfix PR. A `release-sync/v<version>` head must target `main`, use the exact title `chore(release): sync v<version> metadata`, retain the `release-metadata-boundary: v<version>` body m...