git/pull-request skill doesn't cover gh issue create, and body-file drafts need a body-only guard

gh issue create --body-file posted a raw scratch draft into a real GitHub issue verbatim, # Title heading and all, duplicating the title inside the body. Filing a2acode#41 today: I'd drafted the issue as one scratch file with # Title / # Body sections (nice for reviewing before posting), then piped the whole file straight into --body-file without splitting it first. The posted issue opened with a "# Title" heading, the title text again, then a "# Body" heading before the actual content.

Caught it immediately by running gh issue view --json body right after filing, out of habit rather than because anything in the flow forced the check. Fixed with a follow-up gh issue edit --body-file pointed at just the body half.

git/pull-request (plugins/git/skills/pull-request/SKILL.md) covers exactly this shape of mistake for PRs, it always drafts to a file and confirms before gh pr create/edit/comment --body-file. But its trigger list is scoped to gh pr create, gh pr edit, gh pr comment. Filing a GitHub issue (as opposed to a PR) against a repo, ours or someone else's, has no equivalent skill at all, so nothing caught the draft-file shape before it hit --body-file.

Two ways to close the gap, not mutually exclusive:

1. Extend pull-request (or add a sibling skill) to cover gh issue create/edit/comment --body-file, with the same "always confirm the draft before posting" step it already has for PRs.
2. Add an explicit rule to whichever skill ends up owning this: a --body-file draft must be body content only, no wrapper headings, no title duplicated inside it. If a scratch draft is written with separate title/body sections for readability, split it into a real title string and a body-only file before the gh call, don't hand the whole thing to --body-file.

Either way, a "verify what actually got posted" step (gh issue/pr view --json body) right after create would have caught this even without the drafting fix, and is cheap enough to be worth adding regardless.

Read plugins/git/skills/pull-request/SKILL.md and compare its gh pr create/edit/comment --body-file guidance with the missing gh issue create/edit/comment flow. Decide whether the existing skill or a sibling skill should own the issue workflow, then cover body-only drafts, confirmation before posting, and post-create verification with gh issue/pr view --json body. Done means the documented flow prevents wrapper headings and duplicated titles from being posted.