feat: get server list for agent connection

この issue には説明がありません。

The issue title suggests adding a feature to retrieve a server list for agent connections. Start by examining the codebase for existing agent connection logic and server management. Look for modules related to networking, agent handling, and configuration. Determine how servers are currently defined and how a list would be exposed or used. The work likely involves modifying the agent protocol and possibly adding new API endpoints or configuration structures.

索引モデルが issue の本文から書いたものです。