Summary

• Add pre-flight detection of PR state and isCrossRepository in Step 2
• Route to Path A (create follow-up PR) when the original PR is merged
• Route to Path B (push to existing head branch) when PR is open and internal
• Abort with a clear message when PR is open but from an external fork

Changes

.claude/skills/pr-fix/SKILL.md

• Step 2: add two new parallel checks (state and isCrossRepository) with a routing table
• Step 3: split into Path A (checkout new fix branch) and Path B (checkout existing head branch)
• Step 7: split into Path A (gh pr create) and Path B (git push, no new PR)
• Step 8: both paths post verification report as PR comment — Path A to the new PR, Path B to the original PR
• Quick Reference: updated to reflect the new three-way routing

Related Issue

Closes #1466

Test Plan

• Merged PR scenario → enters Path A, creates follow-up PR, posts comment to new PR
• Open internal-branch PR scenario → enters Path B, pushes to head branch, posts comment to original PR
• Open fork PR scenario → aborts with prompt to wait for merge