Add AI agent readiness documentation

[gwenneg]

• Created 7 domain-specific guideline files in docs/:

  • security-guidelines.md: Auth model, PSK validation, input sanitization
  • performance-guidelines.md: Rate limiting, timeouts, Kafka concurrency
  • error-handling-guidelines.md: Logging levels, HTTP errors, error wrapping
  • api-contracts-guidelines.md: OpenAPI specs, pagination, Kafka messages
  • database-guidelines.md: GORM patterns, migrations, query patterns
  • testing-guidelines.md: Ginkgo v2 framework, test patterns, mocks
  • integration-guidelines.md: Clowder, Kafka, S3/MinIO, CloudWatch

• Created AGENTS.md: Agent onboarding guide with cross-cutting conventions, repository structure, architectural patterns, and docs index

• Created CLAUDE.md: Claude Code-specific build/test commands and workflow preferences, imports AGENTS.md for general guidance

• Created .coderabbit.yaml: Configured CodeRabbit to enforce guideline files during PR reviews

• Enhanced README.md: Added tech stack, project structure, enhanced build/test instructions, and documentation table linking to all guides

What?

Explain what the change is linking any relevant JIRAs or Issues.

Why?

Consider what business or engineering goal does this PR achieves.

How?

Describe how the change is implemented. Any noteable new libaries, APIs, or features.

Testing

Did you add any tests for the change?

Anything Else?

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Secure Coding Practices Checklist Link

• https://github.com/RedHatInsights/secure-coding-checklist

Secure Coding Checklist

• Input Validation
• Output Encoding
• Authentication and Password Management
• Session Management
• Access Control
• Cryptographic Practices
• Error Handling and Logging
• Data Protection
• Communication Security
• System Configuration
• Database Security
• File Management
• Memory Management
• General Coding Practices