Describe the feature or problem you'd like to solve

When the GitHub MCP Server posts comments (on issues, pull requests, etc.) on behalf of a user, there is no indication to other repository participants that the comment was generated by an AI agent rather than written directly by the user. This creates a transparency gap: reviewers and collaborators have few ways to know whether a comment reflects the user's own words or was autonomously generated and posted by an agent acting on their behalf.

Proposed solution

Add an opt-in configuration option that appends a short disclosure footer to any comment or review body created via the MCP Server. For example:

---
*This comment was posted by an AI agent via the [GitHub MCP Server](https://github.com/github/github-mcp-server) on behalf of @username.*