First open creates a session whose DB row the gateway persists lazily on the
first prompt, so a freshly created (never prompted) session CANNOT be resumed.
Any WS reconnect while sitting on it — tab switch + socket blip, app
background, gateway restart — re-fired session.resume on that key; the gateway
answered 4007 "session not found" and the bounded retry (desktop parity, #766)
burned its budget on a permanently invalid key, leaving an error popup whose
Retry could never succeed.
- Skip the reconnect re-resume (and the doomed REST transcript fetch) while the
current session has no confirmed server-side row (REST 200 / resume success /
first MessageStart = first prompt accepted). Sessions picked from History
stay optimistic-resumable even while their page transiently 5xxes.
- Treat a definitive "session not found" (4007 RPC / 404 REST) as terminal:
recover with a fresh chat + notice instead of the dead-end Retry overlay.
- session.branch: keep the storage key in currentSessionId (the handler stored
the runtime registry id, so every later resume 4007'd and the transcript 404).
Tests: reconnect on an unconfirmed session must not resume or error; 4007 must
recover with a new session (deduped, notice shown); branch keeps the storage id
(currentSessionId + transcript fetch key). RED-GREEN proven: all three fail on
the pre-fix code and pass with it.
Co-authored-by: M57 <hy4ri@users.noreply.github.com>
