feat: Add MCP client

[mkmeral]

Description

This PR adds comprehensive MCP (Model Context Protocol) integration to Strands CLI, enabling agents to connect to and use external tools and services through standardized MCP servers.

Key features:

• MCP Client Support: Connect to any MCP server via stdio or SSE transports
• Multi-Server Connections: Support for multiple simultaneous MCP connections
• Automatic Tool Loading: Tools from MCP servers are automatically loaded and available to agents
• Flexible Configuration: Configure via command line argument, JSON file, or environment variable
• Graceful Lifecycle Management: Automatic connection on startup and disconnection on exit

The implementation includes:

• New mcp_utils.py module for MCP configuration loading and connection management
• --mcp-config command line argument for specifying MCP server configurations
• Integration with the mcp_client tool for server communication
• Comprehensive error handling and status reporting
• Full test coverage for all MCP functionality

Type of Change

• New feature

Testing

All tests have been added and are passing:

• hatch fmt --linter ✅
• hatch fmt --formatter ✅
• hatch test --all ✅

Added comprehensive test coverage:

• test_strands_mcp_integration.py - Tests for MCP integration in main module
• test_mcp_utils.py - Tests for MCP utility functions
• Tests cover configuration loading, connection initialization, disconnection, and error handling

Additionally tested using mcp.json below

{
  "mcpServers": {
    "perplexity-ask": {
      "command": "docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "-e",
        "PERPLEXITY_API_KEY",
        "mcp/perplexity-ask"
      ],
      "env": {
        "PERPLEXITY_API_KEY": "REDACTED"
      }
    },
    "github": {
      "command": "docker",
      "args": [
        "run",
        "-i",
        "--rm",
        "-e",
        "GITHUB_PERSONAL_ACCESS_TOKEN",
        "ghcr.io/github/github-mcp-server"
      ],
      "env": {
        "GITHUB_PERSONAL_ACCESS_TOKEN": "REDACTED"
      }
    }
  }
}

Checklist

• I have read the CONTRIBUTING document
• I have added tests that prove my fix is effective or my feature works
• I have updated the documentation accordingly
• I have added an appropriate example to the documentation to outline the feature
• My changes generate no new warnings
• [] Any dependent changes have been merged and published
  • No. This change depends on feat: Add MCP client tool tools#49

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice

[awsarron]

Related: #4