Add /health endpoint for Docker healthcheck

The healthcheck was hitting /mcp which requires auth, causing unhealthy status.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Dockerfile

@@ -35,7 +35,7 @@ EXPOSE 8000
 
 # Health check
 HEALTHCHECK --interval=30s --timeout=10s --start-period=5s --retries=3 \
-    CMD python -c "import urllib.request; urllib.request.urlopen('http://localhost:8000/mcp')" || exit 1
+    CMD python -c "import urllib.request; urllib.request.urlopen('http://localhost:8000/health')" || exit 1
 
 # Use entrypoint to fix permissions, then run as mcp user
 ENTRYPOINT ["/entrypoint.sh"]