Sent message incorrectly marked "not sent" after provider error (LX-111)

Summary:

While the model was thinking on a very long task, it returned the error: "The model provider rejected or could not complete this request. Please try again in a moment. (LX-111)". The user's prompt was then marked "not sent" with an option to "resend message."

This is misleading: the message was sent and processed - the model was actively thinking on it and had produced very long reasoning text. That reasoning text disappeared and was replaced by the error message.

Actual Result:

• The prompt is marked "not sent" with a "resend message" option.

• The reasoning text that was already generated disappears.

• The error message (LX-111) takes its place.

• The user is led to believe the message never reached the model, when in fact it was sent and partially processed.

Expected Result:

• The message should not be marked "not sent" - it was delivered and processed. A more accurate state would be "failed" or "error during processing."

• The reasoning text generated before the failure should be preserved (or at least its loss acknowledged), not silently replaced by the error.

• The "resend" option should be framed as a retry of the request, not a resend of an unsent message.