feat: remote compaction (#6795)

Co-authored-by: pakrym-oai <pakrym@openai.com>

codex-rs/core/src/rollout/policy.rs

@@ -27,7 +27,8 @@ pub(crate) fn should_persist_response_item(item: &ResponseItem) -> bool {
         | ResponseItem::CustomToolCall { .. }
         | ResponseItem::CustomToolCallOutput { .. }
         | ResponseItem::WebSearchCall { .. }
-        | ResponseItem::GhostSnapshot { .. } => true,
+        | ResponseItem::GhostSnapshot { .. }
+        | ResponseItem::CompactionSummary { .. } => true,
         ResponseItem::Other => false,
     }
 }

codex-rs/core/src/rollout/tests.rs

@@ -814,6 +814,7 @@ async fn test_tail_skips_trailing_non_responses() -> Result<()> {
         timestamp: format!("{ts}-compacted"),
         item: RolloutItem::Compacted(CompactedItem {
             message: "compacted".into(),
+            replacement_history: None,
         }),
     };
     writeln!(file, "{}", serde_json::to_string(&compacted_line)?)?;