Support paginated thread history in app-server list APIs (#33152)

## Why

Clients could discover threads with paginated history, but could not page their
turns through `thread/turns/list`.

## What changed

- Route `thread/turns/list` for paginated threads through the thread store,
  preserving cursors, sort direction, turn status, timing, errors, and the
  requested `summary` or `notLoaded` item view.
- Reject the `full` turn item view for paginated threads and direct clients to
  `thread/items/list` for complete item pagination.
- Return each item page entry with both its containing `turnId` and `item`, so
  clients can regroup thread-wide pages into turns.
- Expose local thread-store turn and item pagination through the `ThreadStore`
  implementation.

## Testing

Added app-server coverage for paging projected turns and items, item views,
cursors, turn metadata, and rejection of the unsupported `full` view.

GitOrigin-RevId: 9c4a127a9b4fa91313f0e87494c62fe2e3a06f19

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

@@ -344,6 +344,14 @@ impl ThreadStore for LocalThreadStore {
         Box::pin(async move { list_threads::list_threads(self, params).await })
     }
 
+    fn list_turns(&self, params: ListTurnsParams) -> ThreadStoreFuture<'_, TurnPage> {
+        Box::pin(LocalThreadStore::list_turns(self, params))
+    }
+
+    fn list_items(&self, params: ListItemsParams) -> ThreadStoreFuture<'_, ItemPage> {
+        Box::pin(LocalThreadStore::list_items(self, params))
+    }
+
     fn search_threads(
         &self,
         params: SearchThreadsParams,