Description

fix #2422
fix #2447

Refresh the database and delete the knowledge base, both perform vector data deletion operations, but the vector database persistence file is occupied by other processes, it cannot be deleted, and the vector collection has been deleted, if it is deleted again, the collection cannot be found, and you need to query whether the collection exists before deleting it

How Has This Been Tested?

Refresh the database or delete the knowledge base

Snapshots:

Include snapshots for easier review.

Checklist:

• My code follows the style guidelines of this project
• I have already rebased the commits and make the commit message conform to the project standard.
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• Any dependent changes have been merged and published in downstream modules