feat(aws-documentation-mcp-server): Add streamable-http transport support

[mengchen-tam]

Fixes #N/A

Summary

Changes

This PR adds support for streamable-http transport mode to the AWS Documentation MCP Server, enabling deployment in containerized environments such as Amazon ECS, Kubernetes, and behind load balancers.

Core Functionality:

• Added FASTMCP_TRANSPORT environment variable to switch between stdio and streamable-http modes
• Added FASTMCP_HOST and FASTMCP_PORT environment variables for HTTP server configuration
• Modified server_aws.py and server_aws_cn.py to pass host/port to FastMCP constructor
• Updated main() function to accept transport parameter

Docker Support:

• Set FASTMCP_HOST=0.0.0.0 as default in Dockerfile for container networking
• Enhanced docker-healthcheck.sh to support HTTP mode health checks

Documentation:

• Added comprehensive HTTP transport mode documentation with Docker and MCP client examples
• Documented all new environment variables

User experience

Before this change:

• Users could only run aws-documentation-mcp-server locally with stdio transport
• No support for containerized deployments or remote access
• Cannot deploy behind load balancers or in multi-user environments

After this change:

• Users can deploy the server in Docker containers with HTTP transport
• Supports deployment on Amazon ECS, Kubernetes, and other container platforms
• Can be accessed remotely through load balancers
• Fully backward compatible - existing stdio configurations continue to work unchanged

Example usage:

# Docker with HTTP mode
docker run -d \
 -p 8000:8000 \
 -e FASTMCP_TRANSPORT=streamable-http \
 -e FASTMCP_HOST=0.0.0.0 \
 -e FASTMCP_PORT=8000 \
 mcp/aws-documentation:latest

Checklist

If your change doesn't seem to apply, please leave them unchecked.

• I have reviewed the contributing guidelines
• I have performed a self-review of this change
• Changes have been tested
• Changes are documented

Is this a breaking change? (Y/N): N

RFC issue number: N/A (This is a feature enhancement following existing patterns in aws-api-mcp-server)

Checklist:

• Migration process documented (not needed - fully backward compatible)
• Implement warnings (not needed - opt-in via environment variables)

Testing

✅ Production tested:

• Deployed and running in production on Amazon ECS Fargate
• Serving requests through Application Load Balancer
• Verified with multiple MCP clients (Kiro CLI)
• Health checks working correctly
• No issues observed after 10+ test iterations

Acknowledgment

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

[github-actions]

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[mengchen-tam]

Still relevant, please let me know if anything needed on my end at the moment :)