fix: Fix when get too long response, message cannot add to mysql data…

[noahc1510]

Description

When I chat with a large database, the LLM will response a large content. The pymysql will feedback this error message: Data too long for column 'message_detail' at row 1. This PR change the type of message_detail from text to longtext.

How Has This Been Tested?

Reproduct that case I wrote before, the bug has been fix.

Snapshots:

Checklist:

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