docs: add AGENTS.md with Cursor Cloud dev environment notes

[barredterra]

Summary

Set up and verified a full development environment for the ask_alyf Frappe app in Cursor Cloud, and captured the durable, non-obvious startup/run caveats in a new AGENTS.md.

This run booted as a just-in-time override (no linked environment / no build), so the committed .cursor/Dockerfile was not applied. I bootstrapped a functionally-equivalent bench in the VM (Python 3.14, Node 24, MariaDB, Redis, Frappe version-16) to prove the setup works end to end. The environment itself remains defined by the committed repo files (.cursor/environment.json → Dockerfile + install.sh + start.sh); no environment/snapshot changes are made here.

What was verified

• Lint — pre-commit run --all-files: ruff, ruff-format, prettier, eslint all pass.
• Tests — bench --site ask-alyf.localhost run-tests --app ask_alyf: Ran 109 tests ... OK.
• App running — bench start (web :8000, socketio :9000); /api/method/ping → pong; login page renders.
• Hello-world chat — logged into Desk as Administrator, opened the Ask ALYF assistant, sent a message. The full pipeline (frontend → send_message → RQ worker → LangChain coordinator → OpenAI Responses API) runs; the worker issues POST https://api.openai.com/v1/responses.

Known blocker (environment, not code)

The AI chat requires network egress to api.openai.com, which is not in the default Cursor Cloud egress allowlist. The external LLM call fails with openai.APIConnectionError: Connection error, and the chat shows the graceful fallback "I hit an error while processing that request." Adding api.openai.com to the egress allowlist unblocks real chat responses.

Changes

• Add AGENTS.md documenting the app, the repo-defined environment, and Cloud-specific run caveats (Python 3.14 / Node 24 requirement, bench location + site name, run/lint/test commands, and the api.openai.com egress requirement).

Artifacts

Ask ALYF assistant open on Frappe Desk
Chat message processed end-to-end (LLM call blocked by egress)

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