Add support for running the MCP server over HTTP with Server-Sent Events
(SSE) using the MCP Streamable HTTP specification, alongside the existing
STDIO transport.
New features:
- Transport abstraction with Transport interface
- HTTP transport with session management
- SSE support for server-initiated notifications
- CORS security with configurable allowed origins
- Optional TLS support
- CLI flags for HTTP configuration (--transport, --http-address, etc.)
- NixOS module options for HTTP transport
The HTTP transport implements:
- POST /mcp: JSON-RPC requests with session management
- GET /mcp: SSE stream for server notifications
- DELETE /mcp: Session termination
- Origin validation (localhost-only by default)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
