Persist agent messages as response items (#29829)

## Why

Inter-agent messages are recorded in live history as
`ResponseItem::AgentMessage`, but rollouts stored
`InterAgentCommunication` and rebuilt the response item during resume.
This made the rollout differ from the actual Responses history.

## What changed

- store the prepared `agent_message` response item directly
- keep `trigger_turn` in a small local metadata record for fork
truncation
- keep reading older `inter_agent_communication` rollout items

codex-rs/rollout/src/list.rs

@@ -1151,6 +1151,7 @@ async fn read_head_summary(path: &Path, head_limit: usize) -> io::Result<HeadTai
                     .created_at
                     .get_or_insert_with(|| rollout_line.timestamp.clone());
             }
+            RolloutItem::InterAgentCommunicationMetadata { .. } => {}
             RolloutItem::TurnContext(_) => {
                 // Not included in `head`; skip.
             }
@@ -1213,7 +1214,8 @@ pub async fn read_head_for_summary(path: &Path) -> io::Result<Vec<serde_json::Va
                         head.push(value);
                     }
                 }
-                RolloutItem::Compacted(_)
+                RolloutItem::InterAgentCommunicationMetadata { .. }
+                | RolloutItem::Compacted(_)
                 | RolloutItem::TurnContext(_)
                 | RolloutItem::EventMsg(_) => {}
             }

codex-rs/rollout/src/metadata.rs

@@ -69,6 +69,7 @@ pub fn builder_from_items(
         RolloutItem::SessionMeta(meta_line) => Some(meta_line),
         RolloutItem::ResponseItem(_)
         | RolloutItem::InterAgentCommunication(_)
+        | RolloutItem::InterAgentCommunicationMetadata { .. }
         | RolloutItem::Compacted(_)
         | RolloutItem::TurnContext(_)
         | RolloutItem::EventMsg(_) => None,
@@ -123,6 +124,7 @@ pub async fn extract_metadata_from_rollout(
             RolloutItem::SessionMeta(meta_line) => meta_line.meta.memory_mode.clone(),
             RolloutItem::ResponseItem(_)
             | RolloutItem::InterAgentCommunication(_)
+            | RolloutItem::InterAgentCommunicationMetadata { .. }
             | RolloutItem::Compacted(_)
             | RolloutItem::TurnContext(_)
             | RolloutItem::EventMsg(_) => None,

codex-rs/rollout/src/persistence_metrics.rs

@@ -227,6 +227,9 @@ fn rollout_item_type(item: &RolloutItem) -> String {
         RolloutItem::SessionMeta(_) => "session_meta".to_string(),
         RolloutItem::ResponseItem(item) => response_item_type(item).to_string(),
         RolloutItem::InterAgentCommunication(_) => "inter_agent_communication".to_string(),
+        RolloutItem::InterAgentCommunicationMetadata { .. } => {
+            "inter_agent_communication_metadata".to_string()
+        }
         RolloutItem::Compacted(_) => "compacted".to_string(),
         RolloutItem::TurnContext(_) => "turn_context".to_string(),
         RolloutItem::EventMsg(EventMsg::ItemCompleted(event)) => {

codex-rs/rollout/src/policy.rs

@@ -6,7 +6,8 @@ use codex_protocol::models::ResponseItem;
 pub fn is_persisted_rollout_item(item: &RolloutItem) -> bool {
     match item {
         RolloutItem::ResponseItem(item) => should_persist_response_item(item),
-        RolloutItem::InterAgentCommunication(_) => true,
+        RolloutItem::InterAgentCommunication(_)
+        | RolloutItem::InterAgentCommunicationMetadata { .. } => true,
         RolloutItem::EventMsg(ev) => should_persist_event_msg(ev),
         // Persist Codex executive markers so we can analyze flows (e.g., compaction, API turns).
         RolloutItem::Compacted(_) | RolloutItem::TurnContext(_) | RolloutItem::SessionMeta(_) => {
@@ -55,7 +56,8 @@ pub fn should_persist_response_item(item: &ResponseItem) -> bool {
 pub fn should_persist_response_item_for_memories(item: &ResponseItem) -> bool {
     match item {
         ResponseItem::Message { role, .. } => role != "developer",
-        ResponseItem::LocalShellCall { .. }
+        ResponseItem::AgentMessage { .. }
+        | ResponseItem::LocalShellCall { .. }
         | ResponseItem::FunctionCall { .. }
         | ResponseItem::ToolSearchCall { .. }
         | ResponseItem::FunctionCallOutput { .. }
@@ -64,7 +66,6 @@ pub fn should_persist_response_item_for_memories(item: &ResponseItem) -> bool {
         | ResponseItem::CustomToolCallOutput { .. }
         | ResponseItem::WebSearchCall { .. } => true,
         ResponseItem::AdditionalTools { .. }
-        | ResponseItem::AgentMessage { .. }
         | ResponseItem::Reasoning { .. }
         | ResponseItem::ImageGenerationCall { .. }
         | ResponseItem::Compaction { .. }

codex-rs/rollout/src/recorder.rs

@@ -1856,6 +1856,7 @@ async fn resume_candidate_matches_cwd(
             RolloutItem::SessionMeta(_)
             | RolloutItem::ResponseItem(_)
             | RolloutItem::InterAgentCommunication(_)
+            | RolloutItem::InterAgentCommunicationMetadata { .. }
             | RolloutItem::Compacted(_)
             | RolloutItem::EventMsg(_) => None,
         })

codex-rs/rollout/src/search.rs

@@ -284,6 +284,7 @@ fn conversation_text_from_item(item: &RolloutItem) -> Option<String> {
         | RolloutItem::EventMsg(_)
         | RolloutItem::ResponseItem(_)
         | RolloutItem::InterAgentCommunication(_)
+        | RolloutItem::InterAgentCommunicationMetadata { .. }
         | RolloutItem::Compacted(_) => None,
     }
 }