docs: add bosun repository configuration

[bosun-ai-staging]

This updates the repository with Bosun configuration so it can be initialized and exercised on the Bosun platform, while documenting the runtime dependencies that should be verified during setup.

Summary

• add .bosun/config.toml with a Bosun setup script, test environment defaults, and service definitions
• add AGENTS.md with repository guidance Bosun can use when working in this Rails codebase
• align the PR messaging with the repository’s existing local runtime requirements

What changed

Bosun configuration

• configure Bosun to:
  • install Ruby and Node dependencies
  • run bin/rails db:prepare when PostgreSQL is reachable
  • use test-focused defaults for:
    • RAILS_ENV
    • DATABASE_URL
    • REDIS_URL
• define the required Bosun services in .bosun/config.toml:
  • postgres (postgres:15-alpine)
  • redis (redis:7-alpine)

Repository guidance

• add AGENTS.md with concise notes on:
  • project structure
  • common setup and test commands
  • Rails and frontend conventions
  • testing and security expectations

Validation and reviewer notes

The repository should now be ready to use with Bosun.

Please verify the following services and configuration are correct for your environment:

• PostgreSQL connection details match the intended Bosun environment
• Redis is available at the configured REDIS_URL
• required secrets are set, including:
  • OPENAI_ACCESS_TOKEN
  • GITHUB_APP_IDENTIFIER
  • GITHUB_APP_KEY
• any environment-specific service overrides still reflect how this repository should run outside Bosun

Files

• .bosun/config.toml
• AGENTS.md
• README.md (reference for required environment values)
• docker-compose.yml (reference for local service expectations)
• Procfile.dev (reference for local process layout)

Created by Bosun task run: afcd3bab-8e93-41cf-8f3f-056af44386c3.

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This pull request is created by bosun, a code maintenance automation platform. For more information, visit bosun.ai.