[BLOG] Introduce OpenSearch Agent Server and ART agent

### Describe the blog post

[BLOG] Introduce OpenSearch Agent Server and ART agent

### Expected Title

Introduce OpenSearch Agent Server

### Authors Name

Mingshi Liu

### Authors Email

mingshl

### Target Draft Date

_No response_

### Blog Post Category

technical

### Target Publication Date

_No response_

### Additional Info

_No response_