feat: make ThreadStore available on ThreadExtensionDependencies (#27439)

Generally useful for extensions.

codex-rs/app-server/src/extensions.rs

@@ -21,6 +21,7 @@ use codex_protocol::error::CodexErr;
 use codex_protocol::protocol::Event;
 use codex_protocol::protocol::EventMsg;
 use codex_rollout::state_db::StateDbHandle;
+use codex_thread_store::ThreadStore;
 
 use crate::outgoing_message::OutgoingMessageSender;
 use crate::thread_state::ThreadListenerCommand;
@@ -34,6 +35,8 @@ pub(crate) struct ThreadExtensionDependencies {
     pub(crate) thread_manager: Weak<ThreadManager>,
     pub(crate) goal_service: Arc<GoalService>,
     pub(crate) executor_skill_provider: Arc<dyn codex_skills_extension::SkillProvider>,
+    /// Process-scoped persistence backend for extensions that need stored thread history.
+    pub(crate) thread_store: Arc<dyn ThreadStore>,
 }
 
 pub(crate) fn thread_extensions<S>(
@@ -51,6 +54,7 @@ where
         thread_manager,
         goal_service,
         executor_skill_provider,
+        thread_store: _thread_store,
     } = dependencies;
     let mut builder = ExtensionRegistryBuilder::<Config>::with_event_sink(event_sink);
     if let Some(state_db) = state_db {

codex-rs/app-server/src/mcp_refresh.rs

@@ -202,6 +202,7 @@ mod tests {
                         thread_manager: thread_manager.clone(),
                         goal_service: Arc::new(codex_goal_extension::GoalService::new()),
                         executor_skill_provider: Arc::clone(&executor_skill_provider),
+                        thread_store: Arc::clone(&thread_store),
                     },
                 ),
                 /*analytics_events_client*/ None,

codex-rs/app-server/src/message_processor.rs

@@ -336,6 +336,7 @@ impl MessageProcessor {
                         thread_manager: thread_manager.clone(),
                         goal_service: Arc::clone(&goal_service),
                         executor_skill_provider: Arc::clone(&executor_skill_provider),
+                        thread_store: Arc::clone(&thread_store),
                     },
                 ),
                 Some(analytics_events_client.clone()),