docs: add AGENTS.md with Cursor Cloud development instructions

[ronros-elementor]

PR Checklist

• The commit message follows our guidelines: https://github.com/elementor/elementor/blob/master/.github/CONTRIBUTING.md

PR Type

• Documentation content changes

Summary

This PR can be summarized in the following changelog entry:

• Add AGENTS.md with Cursor Cloud-specific development instructions for autonomous agents.

Description

Adds an AGENTS.md file at the repository root containing instructions for Cursor Cloud agents to set up and work with the Elementor development environment. This includes:

• System requirements (Node.js 20.19, PHP, Composer)
• Repository structure overview (main repo + turbo-repo)
• How to run the application (WordPress Playground, wp-lite-env)
• Development mode (npm run watch)
• Linting, testing, and build commands
• Known gotchas (composer post-install hooks, dev vs no-dev mode, lint-staged memory settings)

Demo of working dev environment

elementor_editor_hello_world_demo.mp4

Elementor editor loaded with drag-and-drop widget placement working:

Elementor editor with Hello from Elementor heading

Test instructions

This PR can be tested by following these steps:

1. Review AGENTS.md for accuracy of documented commands
2. No functional code changes — documentation only

Quality assurance

• I have tested this code to the best of my abilities
• I have added unittests to verify the code works as intended
• Docs have been added / updated (for bug fixes / features)

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