Re-add history entries for native agent threads (#36500)

Closes #ISSUE

Release Notes:

- N/A

---------

Co-authored-by: Antonio Scandurra <me@as-cii.com>

crates/agent2/src/agent2.rs

@@ -1,4 +1,6 @@
 mod agent;
+mod db;
+mod history_store;
 mod native_agent_server;
 mod templates;
 mod thread;
@@ -9,6 +11,8 @@ mod tools;
 mod tests;
 
 pub use agent::*;
+pub use db::*;
+pub use history_store::*;
 pub use native_agent_server::NativeAgentServer;
 pub use templates::*;
 pub use thread::*;