[BUG] '🤖 Generated with Claude Code' footer never appears in squashed PR commit bodies

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report
• [x] I am using the latest version of Claude Code

What's Wrong?

The system prompt instructs:

End PR bodies with:
🤖 Generated with [Claude Code](https://claude.com/claude-code)

This line never appears in squashed PR commit bodies. Every PR merged via squash merge is missing this footer.

Reproduction Data

60/60 commits in the last 60 of a real repo are missing the 🤖 footer:

git log --format='%B' -60 | grep -c '🤖 Generated with'
# 0 — zero occurrences in 60 commits

All 60 commits are squash-merged PRs with (#NNN) in the subject line.

What Should Happen?

Either:

1. The 🤖 line should be appended to PR bodies before squash merge, or
2. The system prompt should remove the claim that PR bodies will end with this line

Related Issues

• #66602 — mentions "and a '🤖 Generated with Claude Code' line to PR bodies" in passing, but the issue is focused on Co-Authored-By copyright