Fix an Issue

From issue number to a PR someone can review. The two failure modes this guards against are fixing what was reported instead of what is wrong, and fixing something that was never reproduced.

Let SKILL=/path/to/this/skill — the directory holding this SKILL.md. Commands run from the repository being worked on, not from the skill directory. Needs Python 3.11+, git, and an authenticated gh with network access; fetch_issue.py is a gh wrapper and can do nothing without it. If gh auth status fails, say so rather than guessing at the issue's contents from its number.

1. Read the issue and what surrounds it

python "$SKILL/scripts/fetch_issue.py" 42
python "$SKILL/scripts/fetch_issue.py" 42 --repo owner/name --format json