feat: add /health endpoint and switch to fastmcp 2.0

- Switch from mcp package to fastmcp>=2.0 for Streamable HTTP support
  - Fixes 405 Method Not Allowed for MCP clients like Gemini CLI
  - MCP endpoint now at /mcp (POST) instead of /sse (GET)
  - Removes MCP_ALLOWED_HOSTS (handled at reverse proxy level)

- Add /health endpoint for Docker health checks
  - Returns {"status": "ok"} (200) or {"status": "degraded"} (503)
  - Enables health checks without transport security issues

- Add curl to Docker image for health checks
- Add healthcheck config to docker-compose files
- Add test-health and test-mcp Makefile targets
- Update documentation

README.md

@@ -33,7 +33,6 @@ A Model Context Protocol (MCP) server for [Komodo](https://komo.do/) Docker mana
 | `KOMODO_URL` | Yes | Komodo Core URL |
 | `KOMODO_API_KEY` | Yes | API key |
 | `KOMODO_API_SECRET` | Yes | API secret |
-| `MCP_ALLOWED_HOSTS` | No | Allowed Host headers |
 
 ### Deploy with Docker Compose
 
@@ -45,14 +44,21 @@ services:
       - KOMODO_URL=https://komodo.example.com
       - KOMODO_API_KEY=your-key
       - KOMODO_API_SECRET=your-secret
-      - MCP_ALLOWED_HOSTS=komodo-mcp.example.io,localhost:*
     ports:
       - "8000:8000"
+    healthcheck:
+      test: ["CMD", "curl", "-f", "http://localhost:8000/health"]
+      interval: 30s
+      timeout: 10s
+      retries: 3
 ```
 
-### Connect MCP Client
+### Endpoints
 
-SSE endpoint: `https://your-host/sse`
+| Endpoint | Method | Description |
+|----------|--------|-------------|
+| `/mcp` | POST | MCP protocol endpoint |
+| `/health` | GET | Health check for Docker |
 
 ## Local Development
 
@@ -67,12 +73,12 @@ make dev
 
 # Test
 make logs
-make test-sse
+make test-mcp
 make stop
 ```
 
 ## Tech Stack
 
 - Python 3.11+ / FastMCP / httpx
-- SSE transport / uvicorn
+- Streamable HTTP transport / uvicorn
 - Docker with multi-stage build