#3472 fix(cli): use a valid trigger when trace push resets the attestation

When the trace push hook adds no AI coding session evidence, it resets the attestation. The reset call used the trigger value `trace-push`. The reset action accepts only `AttestationResetTriggerFailed` and `AttestationResetTriggerCancelled`, so the reset was not valid. The hook now uses `AttestationResetTriggerCancelled`.

AI disclosure: this change was made with help from Claude Code.