Currently, the `searches` API lacks a default reranking mechanism. To improve search result relevance, we should add default reranking. **Proposed Changes:** * Implement default reranking for all `searches` API calls. * Introduce a parameter (e.g., `enable_rerank`) to control whether reranking is applied. * This parameter should default to `True`. * When `True`, the system's default reranking model will be used.