Add agent handoff docs and readiness checks

[EShener]

Hi, Async Code is a strong fit for a small agent handoff file because the repo itself runs Claude Code / Codex-style coding agents in parallel, and future contributors are likely to use agent tools while editing it.

I ran a local dry run with agent-ready against the repo. It estimated readiness at 56/100 -> 81/100 with the team preset.

The useful, repo-specific pieces look like:

• add a compact root AGENTS.md that points coding agents to README.md, docker-compose.yml, server/, async-code-web/, Dockerfile.claude-automation, Dockerfile.codex-automation, server/github_integration.py, and server/git_operations.py
• document verification commands agents should try before PRs, for example docker-compose up --build -d, frontend checks from async-code-web/ such as npm run build and npm run lint, plus the existing API smoke script ./test-api.sh when the backend is running
• call out safety-sensitive areas: GitHub token handling, ANTHROPIC_API_KEY, Supabase service-role keys, Docker execution, repository cloning, automated commits, and PR creation
• add small shims for Claude/Cursor/Gemini/Copilot so different coding-agent tools read the same canonical handoff guidance
• optional CI/readiness workflow can make these expectations visible in PRs

The dry run also flagged missing root-level test/lint commands. Since this repo is split across Docker, Flask, and Next.js, it may be enough to document the per-service commands rather than forcing everything into one root script.

Reproduce without writing files:

npx --yes @eshen_fox_mie/agent-ready improve --preset team --dry-run --format issue

The check is local-only and does not require API keys. If this direction is useful, I can follow up with a small PR focused only on the handoff docs/readiness workflow. If not, feel free to close.