✨ Add Appworld tool

[kellyaa]

Summary

This PR introduces a new appworld_apis MCP tool and container runtime so AppWorld can be deployed as a single service exposing both REST APIs and MCP endpoints.

What Changed

• Added mcp/appworld_apis/Dockerfile:
  • Builds from python:3.12-slim-bookworm
  • Clones and installs StonyBrookNLP/appworld with MCP extras
  • Runs as non-root user
  • Installs/downloads AppWorld assets during image build
  • Exposes ports 8000 (REST) and 8001 (MCP)
  • Sets runtime env for on-disk APIs and HTTP MCP transport
• Added mcp/appworld_apis/entrypoint.py:
  • Starts both AppWorld APIs and MCP server in separate processes
  • Handles clean shutdown on SIGTERM/SIGINT
  • Applies Docker-mode DB path guardrails so DB paths stay under:
    • APPWORLD_ROOT/data
    • APPWORLD_ROOT/experiments/outputs
  • Normalizes legacy/absolute DB paths into container-local paths
• Added mcp/appworld_apis/README.md:
  • Deployment guidance for Kagenti
  • Documents current Kagenti multi-port UI bug and manual Deployment/Service workaround for port 8001

Notes / Risks

• Kagenti currently requires a manual post-deploy patch to expose MCP port 8001 (documented in README).

Related issue(s)

#112