- Introduced logic to trigger a follow-up turn when the manual opener greeting is empty.
- Updated `_execute_manual_opener_tool_calls` to return structured tool call and result data.
- Added `_build_manual_opener_follow_up_context` method to construct context for follow-up turns.
- Modified `_handle_turn` to accept system context for improved conversation management.
- Enhanced tests to validate the new follow-up behavior and ensure proper context handling.
- Introduced `manual_opener_tool_calls` field in the Assistant model to support custom tool calls.
- Updated AssistantBase and AssistantUpdate schemas to include the new field.
- Implemented normalization and migration logic for handling manual opener tool calls in the API.
- Enhanced runtime metadata to include manual opener tool calls in responses.
- Updated tests to validate the new functionality and ensure proper handling of tool calls.
- Refactored tool ID normalization to support legacy tool names for backward compatibility.
