Add CRUD functionality for knowledge bases, including routes for listing, creating, updating, and deleting knowledge bases. Update the assistant model to include foreign key references to knowledge bases and modify the assistant configuration to handle external API keys securely. Refactor related services and routes to accommodate these changes, ensuring proper handling of credential resolution and configuration normalization.
Implement a new feature that allows users to create a copy of an existing assistant. The duplicate is inserted after the original, with the name suffixed by "副本" and the updated timestamp. Update the state management to handle the list of assistants accordingly, and add a dropdown menu item for triggering the duplication.
