After the app restarted, the remote backend wrote the next request to
the old, closed connection and reported that the operation may have
completed, although the restarted app received nothing. Reused
connections are now checked without blocking before writing, and a
closed one is replaced first. If the app can't be reached, the error
says so and that nothing was sent. Failures after the request was
written still report uncertainty and are never replayed.
Loopback tests cover a restart between calls (the edit is applied
exactly once) and a refused reconnect. The lost-reply test from #1246
still passes.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BSB7fMQUccqFQekksDGWpo
16366ce422