chore: add AGENTS.md

[matifali]

Summary

• Adds comprehensive AGENTS.md documentation for AI coding assistants
• Provides guidance on project structure, development commands, and testing workflows
• Includes specific instructions for Terraform module development and validation

Test plan

• Validate document formatting and structure
• Verify all referenced commands work correctly
• Test that instructions align with existing project workflows

🤖 Generated with Claude Code

[Copilot]

Pull Request Overview

This PR adds comprehensive documentation for AI coding assistants working with the Coder Registry repository. The documentation provides structured guidance on project organization, development workflows, and testing requirements.

Key changes:

• Creates AGENTS.md with detailed project overview and development guidelines
• Adds reference files (CLAUDE.md and .github/copilot-instructions.md) that point to the main documentation
• Establishes standardized documentation for AI assistant interactions

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
AGENTS.md	Main documentation file containing project overview, development commands, testing workflows, and architectural guidance
CLAUDE.md	Reference file pointing to AGENTS.md for Claude AI assistant
.github/copilot-instructions.md	Reference file pointing to AGENTS.md for GitHub Copilot

---

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.}

[DevelopmentCats]

There was a formatting issue that was caused after a merge for formatting updates was made, and then a merge for kiro, cursor, and windsurf were made without those formatting updates in the branch since it was commit right before.

Since its just for the tests and it shouldn't require a version bump in the modules, it should be safe to make the update here so that future CI will pass.