Description

The pr-fix skill currently always creates a follow-up PR, which is unnecessary when the original PR is still open and comes from an internal branch.

Context

Three scenarios need to be handled differently:

• Merged PR (any source): create a follow-up fix PR (existing behavior)
• Open PR from internal branch: push fixes directly to the head branch so the existing PR updates automatically
• Open PR from external fork: abort with a clear message — direct push is not possible

This change adds pre-flight detection of state and isCrossRepository to route to the correct path.