fix: guard issue async callbacks against a killed buffer

pearl--push-issue-field (the field setters) and pearl-refresh-current-issue ran goto-char on the captured marker in their success callbacks with no liveness check. If the buffer was killed before the async response returned, the dead marker signaled "Marker does not point anywhere" from the callback. I wrapped the buffer work in a buffer-live-p check; the field setters still report the remote success, and refresh reports that the buffer was closed.

This closes the last gap in the command/context test-coverage task. The other seven items it named were already covered by the quick-bug batch's tests; this adds the killed-buffer regression for the issue paths (delete-current-comment already had its own).

0 files changed, 0 insertions, 0 deletions