Implement streamable HTTP transport and improve development tooling

[jacknagz]

Summary

• Implements streamable HTTP transport to replace SSE transport
• Fixes integration tests for reliable HTTP transport testing
• Adds comprehensive repository documentation and development tooling

Key Changes

Streamable HTTP Transport Implementation

• Replace SSE transport with FastMCP's streamable-HTTP in server.py
• Update CLI options and help text for new transport type
• Add proper error handling and graceful shutdown
• Update documentation with streamable-HTTP examples

Integration Test Fixes

• Fix streaming HTTP transport test that was failing with connection errors
• Replace unreliable subprocess approach with threading for server startup
• Handle expected 404 responses for root path (MCP servers don't expose general web interface)
• Use correct /mcp/ endpoint with trailing slash to avoid redirects
• Add proper server startup validation and error reporting

Development Tooling & Documentation

• Add CLAUDE.md with essential development commands and architecture overview
• Document MCP server patterns, registry system, and permission model
• Include environment configuration and testing guidelines
• Update README files with comprehensive transport examples

Test Plan

• Integration tests now pass reliably
• Streamable HTTP transport starts and accepts connections
• MCP client can connect and execute tools over HTTP
• Server handles graceful shutdown properly
• Documentation is complete and accurate

🤖 Generated with Claude Code

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[jacknagz]

@darwayne, this one is looking ready for final review. I'm curious how you'd recommend stdio vs. sse for docker images.