bugfix: fix chatmessage pagination for standard queries

[AnwarRezk]

Summary

• apply page and limit to the default GET /api/v1/chatmessage/:id query path
• add regression coverage for paginated and unpaginated chat message retrieval
• fix the case where paginated requests could return the full dataset instead of the requested page

Problem

GET /api/v1/chatmessage/:id was already accepting pagination parameters, but the standard ChatMessage.find(...) path in utilGetChatMessage did not apply them.
As a result, requests such as:
/api/v1/chatmessage/:id?page=2&limit=100
could return the same full message set as page 1 instead of the requested slice.

Root Cause

In packages/server/src/utils/getChatMessage.ts, the non-feedback query path passed filters and ordering to TypeORM, but did not set skip/take.

Fix

• add skip and take to the default query when both page and pageSize are valid
• leave unpaginated behavior unchanged when pagination is not requested

Testing

• added packages/server/src/utils/getChatMessage.test.ts
• verified:
  • paginated queries apply skip and take
  • unpaginated queries leave them unset

Related Issues

• closes GET /api/v1/chatmessage ignores limit and page parameters for AgentFlow chatflows #6296
• related to Pagination not working for AgentFlow in /api/v1/chatmessage endpoint #6297

[gemini-code-assist]

Code Review

This pull request implements pagination for the utilGetChatMessage function by adding skip and take parameters to the database query. It also includes unit tests to verify that pagination is correctly applied when page and pageSize are provided and ignored when they are not. I have no feedback to provide.