Closes a RAG workspace, releasing in-memory resources (Corestore, HyperDB adapter, RAG instance).
**Workspace lifecycle:** Workspaces are implicitly opened. This function explicitly closes them, releasing memory and file locks. The workspace data remains on disk unless `deleteOnClose` is set to true.
// Close a specific workspaceawait ragCloseWorkspace({ workspace: "my-docs" });// Close and delete in one callawait ragCloseWorkspace({ workspace: "my-docs", deleteOnClose: true });