* Refactor API fetch calls to use a unified fetch function; enhance chat history loading with new hooks and UI components
- Replaced `fetchWithAuth` with a generic `fetch` function across various API modules for consistency.
- Updated `useThreadStream` and `useThreadHistory` hooks to manage chat history loading, including loading states and pagination.
- Introduced `LoadMoreHistoryIndicator` component for better user experience when loading more chat history.
- Enhanced message handling in `MessageList` to accommodate new loading states and history management.
- Added support for run messages in the thread context, improving the overall message handling logic.
- Updated translations for loading indicators in English and Chinese.
* Fix test assertions for run ordering in RunManager tests
- Updated assertions in `test_list_by_thread` to reflect correct ordering of runs.
- Modified `test_list_by_thread_is_stable_when_timestamps_tie` to ensure stable ordering when timestamps are tied.
DanielWalnut