Feat/http sse transport (#9)

* feat: add HTTP/SSE transport for remote MCP access

Add HTTP server with Server-Sent Events (SSE) transport to enable
remote access to the MCP server from Claude Code CLI and other clients.

Features:
- Modular architecture with separated concerns (auth, config, routes)
- API key authentication with multiple methods (Bearer, X-API-Key, query)
- Health check endpoint for monitoring
- Dual transport support (STDIO + HTTP/SSE)
- Railway deployment ready with Dockerfile
- Comprehensive documentation

New files:
- src/late/mcp/constants.py - Global constants
- src/late/mcp/config.py - Configuration management
- src/late/mcp/auth.py - API key authentication
- src/late/mcp/routes.py - Route handlers
- src/late/mcp/http_server.py - Main HTTP server
- Dockerfile - Container configuration for Railway
- .dockerignore - Docker build optimization
- docs/HTTP_DEPLOYMENT.md - Deployment guide

Modified:
- pyproject.toml - Added starlette, uvicorn dependencies
- server.py - Added main() function for STDIO entry point
- README.md - Added HTTP deployment documentation
- .env.example - Added MCP server configuration

* fix: resolve linting errors (UP045, ARG001)

- Replace Optional[X] with X | None for modern type hints
- Prefix unused request parameters with underscore

* fix: make Dockerfile compatible with Railway

- Add id parameter to cache mount (Railway requirement)
- Use PORT environment variable with fallback to 8080
- Remove HEALTHCHECK (Railway handles this externally)

* feat: configure Railway with Railpack instead of Dockerfile

- Add railway.toml with Railpack (NIXPACKS) configuration
- Rename Dockerfile to Dockerfile.docker to prevent auto-detection
- Railpack will auto-detect Python + uv from main.py
- Configure health check path and restart policy

* fix: include README.md in Docker build

README.md is required by hatchling build backend for the package

* fix: use Dockerfile for Railway deployment

- Configure railway.toml to use DOCKERFILE builder
- Restore Dockerfile with proper MCP extras installation
- Remove main.py wrapper (no longer needed)
- Keep pyproject.toml clean with optional dependencies

This approach is more explicit and reproducible than relying on
auto-detection from Railpack/Nixpacks.

---------

Co-authored-by: Carlos Martínez <carlimvg02@gmail.com>

Author: getlatedev

main.py

@@ -1,15 +1,9 @@
 [build]
-# Use Railpack (auto-detects Python + uv)
-builder = "NIXPACKS"
+builder = "DOCKERFILE"
+dockerfilePath = "Dockerfile"
 
 [deploy]
-# Start command for the HTTP server
-startCommand = "python main.py"
-
-# Health check configuration
 healthcheckPath = "/health"
 healthcheckTimeout = 100
-
-# Restart policy
 restartPolicyType = "on_failure"
 restartPolicyMaxRetries = 3