Persist multi-agent runtime metadata (#25721)

Stack split from #25708. Original PR intentionally left open. This
second PR persists multi-agent runtime metadata through thread creation,
rollout recording, and thread storage.

codex-rs/thread-store/src/in_memory.rs

@@ -11,6 +11,9 @@ use codex_protocol::ThreadId;
 use codex_protocol::models::PermissionProfile;
 use codex_protocol::protocol::AskForApproval;
 use codex_protocol::protocol::RolloutItem;
+use codex_protocol::protocol::SessionMeta;
+use codex_protocol::protocol::SessionMetaLine;
+use codex_protocol::protocol::ThreadMemoryMode;
 
 use crate::AppendThreadItemsParams;
 use crate::ArchiveThreadParams;
@@ -164,7 +167,32 @@ impl ThreadStore for InMemoryThreadStore {
     async fn create_thread(&self, params: CreateThreadParams) -> ThreadStoreResult<()> {
         let mut state = self.state.lock().await;
         state.calls.create_thread += 1;
-        state.histories.entry(params.thread_id).or_default();
+        let session_meta = SessionMeta {
+            id: params.thread_id,
+            forked_from_id: params.forked_from_id,
+            parent_thread_id: params.parent_thread_id,
+            cwd: params.metadata.cwd.clone().unwrap_or_default(),
+            agent_nickname: params.source.get_nickname(),
+            agent_role: params.source.get_agent_role(),
+            agent_path: params.source.get_agent_path().map(Into::into),
+            source: params.source.clone(),
+            thread_source: params.thread_source,
+            model_provider: Some(params.metadata.model_provider.clone()),
+            base_instructions: Some(params.base_instructions.clone()),
+            dynamic_tools: (!params.dynamic_tools.is_empty()).then(|| params.dynamic_tools.clone()),
+            memory_mode: matches!(params.metadata.memory_mode, ThreadMemoryMode::Disabled)
+                .then_some("disabled".to_string()),
+            multi_agent_version: params.multi_agent_version,
+            ..SessionMeta::default()
+        };
+        state
+            .histories
+            .entry(params.thread_id)
+            .or_default()
+            .push(RolloutItem::SessionMeta(SessionMetaLine {
+                meta: session_meta,
+                git: None,
+            }));
         state.created_threads.insert(params.thread_id, params);
         Ok(())
     }
@@ -172,7 +200,11 @@ impl ThreadStore for InMemoryThreadStore {
     async fn resume_thread(&self, params: ResumeThreadParams) -> ThreadStoreResult<()> {
         let mut state = self.state.lock().await;
         state.calls.resume_thread += 1;
-        state.histories.entry(params.thread_id).or_default();
+        if let Some(history) = params.history {
+            state.histories.insert(params.thread_id, history);
+        } else {
+            state.histories.entry(params.thread_id).or_default();
+        }
         if let Some(rollout_path) = params.rollout_path {
             state.rollout_paths.insert(rollout_path, params.thread_id);
         }

codex-rs/thread-store/src/local/create_thread.rs

@@ -35,7 +35,8 @@ pub(super) async fn create_thread(
             params.thread_source,
             params.base_instructions,
             params.dynamic_tools,
-        ),
+        )
+        .with_multi_agent_version(params.multi_agent_version),
     )
     .await
     .map_err(|err| ThreadStoreError::Internal {

codex-rs/thread-store/src/local/mod.rs

@@ -1019,6 +1019,7 @@ mod tests {
             thread_source: None,
             base_instructions: BaseInstructions::default(),
             dynamic_tools: Vec::new(),
+            multi_agent_version: None,
             metadata: thread_metadata(),
         }
     }

codex-rs/thread-store/src/types.rs

@@ -9,6 +9,7 @@ use codex_protocol::models::PermissionProfile;
 use codex_protocol::openai_models::ReasoningEffort;
 use codex_protocol::protocol::AskForApproval;
 use codex_protocol::protocol::GitInfo;
+use codex_protocol::protocol::MultiAgentVersion;
 use codex_protocol::protocol::RolloutItem;
 use codex_protocol::protocol::SessionSource;
 use codex_protocol::protocol::ThreadMemoryMode as MemoryMode;
@@ -72,6 +73,8 @@ pub struct CreateThreadParams {
     pub base_instructions: BaseInstructions,
     /// Dynamic tools available to the thread at startup.
     pub dynamic_tools: Vec<DynamicToolSpec>,
+    /// Multi-agent runtime selected when the thread was created.
+    pub multi_agent_version: Option<MultiAgentVersion>,
     /// Metadata captured for the newly created thread.
     pub metadata: ThreadPersistenceMetadata,
 }