Add ctester utility for testing LLM agents

[asdek]

Description of the Change

This PR introduces the ctester utility for testing LLM agents. The utility enables developers to validate and optimize LLM agent performance through automated testing.

Problem

The project lacked a dedicated utility for testing LLM agents, making it difficult to validate their functionality and optimize model selection.

Solution

• Added the ctester utility with comprehensive test suites for various agent types
• Implemented parallel testing capabilities for improved efficiency
• Added detailed reporting with success rates and latency metrics
• Created flexible configuration options for testing different providers

Closes #14

Type of Change

• 🚀 New feature (non-breaking change which adds functionality)
• 📚 Documentation update
• 🔧 Configuration change

Areas Affected

• Core Services (Frontend UI/Backend API)
• AI Agents (Researcher/Developer/Executor)
• External Integrations (LLM/Search APIs)
• Documentation
• Infrastructure/DevOps

Testing and Verification

Test Steps

1. Build the Docker image with the updated Dockerfile
2. Run ctester with various agent types
3. Review generated reports for performance metrics

Documentation Updates

• README.md updates with detailed instructions for:
  • Using the utility as a developer (local Go environment)
  • Using the utility as an external user (Docker)
  • Available command-line options
  • Example provider configurations

Deployment Notes

No special considerations for deployment; the utility is built during Docker image creation.

Additional Notes

This utility will help improve LLM agent reliability by identifying optimal model configurations for different agent types.