Add app-server compaction item notifications tests (#10123)

- add v2 tests covering local + remote auto-compaction item
started/completed notifications

codex-rs/app-server/tests/suite/v2/mod.rs

@@ -2,6 +2,7 @@ mod account;
 mod analytics;
 mod app_list;
 mod collaboration_mode_list;
+mod compaction;
 mod config_rpc;
 mod dynamic_tools;
 mod initialize;