After pushing the fix branch, automatically merge it back to main and
push, so that CI/CD is triggered with the fix. Also cleans up the
remote fix branch after merge.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
push() was failing for new fix branches because they had no upstream
tracking branch. Now uses set_upstream=True with explicit refspec.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>