fix-linting-types-on-pr

MEDIUM W011: Third-party content exposure detected (indirect prompt injection risk).

• Third-party content exposure detected (high risk: 0.90). The SKILL.md explicitly instructs the agent to "gh pr checkout <PR_NUMBER>" to check out PRs (including fork PRs) and then run linting/TypeScript checks and edit files, so it fetches and interprets untrusted, user-generated repository content from external PRs which can materially influence edits and tool actions.