mcp dependency has no upper bound — breaks on mcp 2.0.0 (ModuleNotFoundError: mcp.server.fastmcp)

## What happened

`pip install -e '.[mcp]'` fails at import time on a fresh install:

```
ModuleNotFoundError: No module named 'mcp.server.fastmcp'
```

## Root cause

The package's `mcp` dependency is pinned as `mcp[cli]>=1.2.0` with no upper bound. The upstream `mcp` SDK shipped a `2.0.0` release that removed `mcp.server.fastmcp` (renamed/restructured), and the sample server imports that module at load time. Any install performed on or after that release resolves to `mcp>=2.0.0` and breaks immediately, with no code changes on the caller's side.

## Workaround

Pin the dependency to the last known-good 1.x release when installing:

```
pip install 'mcp==1.29.0'
```

## Suggested fix

Add an upper bound in `pyproject.toml`, e.g. `mcp[cli]>=1.2.0,<2`, until the server is updated for the `mcp` 2.x API.

## Context

Hit this 2026-08-23 while integrating this MCP server into an external client ([victoria-gateway](https://github.com/GordonWei/victoria-gateway)) against a live AWS DevOps Agent instance. Happy to open a PR with the pin if that's preferred over a report.

Start in pyproject.toml and inspect the mcp optional dependency, then reproduce the failure with pip install -e '.[mcp]' on a fresh environment. Done means dependency resolution stays below version 2 and the sample server imports successfully without ModuleNotFoundError.

Written by the indexing model from the issue text.