Act on reasoning-included per turn (#9402)

- Reset reasoning-included flag each turn and update compaction test

codex-rs/otel/src/traces/otel_manager.rs

@@ -484,6 +484,7 @@ impl OtelManager {
             ResponseEvent::ReasoningSummaryPartAdded { .. } => {
                 "reasoning_summary_part_added".into()
             }
+            ResponseEvent::ServerReasoningIncluded(_) => "server_reasoning_included".into(),
             ResponseEvent::RateLimits(_) => "rate_limits".into(),
             ResponseEvent::ModelsEtag(_) => "models_etag".into(),
         }