Add AGENTS.md (comprehensive agent guide)

[PeterDaveHello]

Mainly generated by codex-cli v0.42.0, with gpt-5-codex high, and this AGENTS.md construction prompt:

• https://gist.github.com/PeterDaveHello/f30c38a156982a35683edfd5ece2d474

This guide captures the repository structure, tooling, and safety checks, enabling contributors and coding agents to quickly grasp the project architecture, stay aligned, and deliver efficient, well-vetted changes with confidence.

Reference:

• https://agents.md/

Summary from GitHub Copilot:

This pull request adds a comprehensive set of repository guidelines to the project documentation. The new AGENTS.md file provides clear instructions for setup, development, testing, code style, commit practices, and security, making it easier for contributors to follow best practices and maintain consistency.

Repository workflow and setup:

• Added guidance on using pinned Node versions with nvm use, running lint and tests, signing commits, and updating release documentation (AGENTS.md).

Project structure and organization:

• Documented the roles of key folders and files, including app.js, lib/**, bin/, utils/, public/, locales/, and test organization under test/.

Development, build, and test commands:

• Provided step-by-step instructions for installing dependencies, running development and production builds, starting the server, linting, and running targeted or full test suites.

Coding style and commit conventions:

• Outlined formatting rules (StandardJS, .editorconfig), naming conventions, and expectations for commit messages and pull requests, including DCO sign-off and atomic commits.

Security and permissions:

• Clarified safe actions, when to seek approval, and security/configuration tips for secrets, headers, and image upload adapters.