Add experimental thread queue APIs to app server (#38456)

## What changed

- Add experimental `thread/queue/add`, `list`, `update`, `delete`, `reorder`, and `start` requests for persistent queued user submissions.
- Automatically dispatch queued submissions in FIFO order after completed or failed turns, while leaving the queue paused after interruption.
- Emit `thread/queue/changed` notifications and expose paginated queue contents with stable submission and client message IDs.
- Export the new protocol types through the generated JSON Schema and TypeScript bindings.

## Testing

- Add app-server integration coverage for capability gating, CRUD, pagination, capacity limits, notifications, automatic dispatch, cold-thread resume, interruption, and explicit queue starts.

GitOrigin-RevId: 89caf5577192199bda77cf6c372a59d26cdd910e

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

@@ -83,7 +83,9 @@ impl QueueStore for LocalQueueStore {
                 .await
                 .map_err(|error| match error.downcast_ref::<sqlx::Error>() {
                     Some(sqlx::Error::RowNotFound) => ThreadStoreError::InvalidRequest {
-                        message: format!("queue cannot contain more than {MAX_QUEUE_ITEMS} items"),
+                        message: format!(
+                            "queue cannot contain more than {MAX_QUEUE_ITEMS} submissions"
+                        ),
                     },
                     _ => ThreadStoreError::Internal {
                         message: format!("queue storage failed: {error}"),