Feature Request: Combine git_add and git_commit MCP commands for better performance

## Problem

When using the Git MCP Server (https://github.com/cyanheads/git-mcp-server), running `git_add` and `git_commit` commands back-to-back is inefficient and slow. These commands are commonly used together, but currently require separate tool invocations that can add 20-30 seconds of unnecessary delay to the workflow.

## Proposed Solution

Add a new combined MCP command that handles both staging and committing in a single operation. This would significantly improve performance when working with Git through MCP clients.

### Potential Implementation

The Git MCP Server could add a new tool like `git_stage_and_commit` that:

1. Takes both file paths to stage and a commit message
2. Performs the staging and commit in a single operation
3. Returns a unified result

Example usage:
```json
{
"path": "/path/to/repo",
"filesToStage": ["file1.txt", "file2.js"],
"message": "feat: add new functionality",
"author": { /* optional */ },
"allowEmpty": false,
"amend": false
}
```

## Benefits

- Reduced latency when working with Git through MCP clients
- More natural workflow that matches how developers typically use Git
- Better user experience with AI assistants that leverage the Git MCP Server

## Reference

This is based on the Git MCP Server repository: https://github.com/cyanheads/git-mcp-server

The current implementation requires separate calls to `git_add` and `git_commit` which introduces significant delays in the workflow.

Start by inspecting the repository's current MCP-related configuration and any invocations of git_add and git_commit. Determine whether the combined operation belongs in this repository or in the referenced Git MCP Server, then define the supported staging, commit, author, empty-commit, and amend inputs; done when one operation stages the requested files and returns a unified commit result.

Written by the indexing model from the issue text.